Editing World Wide Web

{{Short description|Linked hypertext system on the Internet}}
{{About|the global system of pages accessed via HTTP|the worldwide computer network|Internet|the web browser|WorldWideWeb}}
{{pp-move}}
{{Redirect-multi|2|WWW|The Web}}
{{Use British English|date=May 2024}}
{{Use dmy dates|date=May 2024}}
{{Infobox technology standard
| title             = World Wide Web
| long_name         = 
| image             = 
| caption           = 
| abbreviation      = WWW
| year_started      = {{Start date and age|1989|df=y}}&nbsp;by [[Tim Berners-Lee]]
| organization      = {{Plain list|
* [[CERN]] (1989–1994)
* [[W3C]] (1994–current)
}}
}}
[[File:Chrome on Linux.png|thumb|260px|A [[web page]] from [[Wikipedia]] displayed in [[Google Chrome]]]]
The '''World Wide Web''' ('''WWW''' or simply '''the Web'''<ref>{{Cite web |title=World Wide Web - MDN Web Docs Glossary: Definitions of Web-related terms {{!}} MDN |url=https://developer.mozilla.org/en-US/docs/Glossary/World_Wide_Web |access-date=2023-04-25 |website=developer.mozilla.org |language=en-US}}</ref>) is an [[information system]] that enables [[Content (media)|content]] sharing over the [[Internet]] through user-friendly ways meant to appeal to users beyond [[Information technology|IT]] specialists and hobbyists.<ref>{{Cite book |title=The Desk Encyclopedia of World History |publisher=[[Oxford University Press]] |year=2006 |isbn=978-0-7394-7809-7 |editor-last=Wright |editor-first=Edmund |location=New York |pages=312}}</ref> It allows documents and other [[web resource]]s to be accessed over the Internet according to specific rules of the [[HTTP|Hypertext Transfer Protocol]] (HTTP).<ref name="webinternet">{{cite web |date=2009 |title=What is the difference between the Web and the Internet? |url=http://www.w3.org/Help/#webinternet |access-date=16 July 2015 |website=W3C Help and FAQ |publisher=[[W3C]] |archive-date=9 July 2015 |archive-url=https://web.archive.org/web/20150709004648/http://www.w3.org/Help/#webinternet |url-status=live }}</ref>

The Web was invented by English computer scientist [[Tim Berners-Lee]] while at [[CERN]] in 1989 and opened to the public in 1993. It was conceived as a "universal linked information system".<ref>{{Cite web |title=World Wide Web (WWW) launches in the public domain {{!}} April 30, 1993 |url=https://www.history.com/this-day-in-history/world-wide-web-launches-in-public-domain |access-date=2025-01-21 |website=HISTORY |date=30 March 2020 |language=en |archive-date=6 February 2025 |archive-url=https://web.archive.org/web/20250206200329/https://www.history.com/this-day-in-history/world-wide-web-launches-in-public-domain |url-status=live }}</ref><ref name="TBL Web Proposal">{{cite web |last1=Berners-Lee |first1=Tim |title=Information Management: A Proposal |url=https://www.w3.org/History/1989/proposal.html |access-date=12 February 2022 |website=w3.org |publisher=The World Wide Web Consortium |archive-date=1 April 2010 |archive-url=https://web.archive.org/web/20100401051011/https://www.w3.org/History/1989/proposal.html |url-status=live }}</ref><ref>{{Cite web |date=2018-08-30 |title=The World's First Web Site |url=https://www.history.com/news/the-worlds-first-web-site |access-date=2023-08-19 |website=HISTORY |language=en |archive-date=19 August 2023 |archive-url=https://web.archive.org/web/20230819131610/https://www.history.com/news/the-worlds-first-web-site |url-status=live }}</ref> Documents and other media content are made available to the network through [[web server]]s and can be accessed by programs such as [[web browser]]s. Servers and resources on the World Wide Web are identified and located through character strings called [[uniform resource locator]]s (URLs).

The original and still very common document type is a [[web page]] formatted in [[Hypertext Markup Language]] (HTML). This markup language supports [[plain text]], [[digital image|images]], embedded [[video]] and [[audio signal|audio]] contents, and [[scripting language|scripts]] (short programs) that implement complex user interaction. The HTML language also supports [[hyperlink]]s (embedded URLs) which provide immediate access to other web resources. [[Web navigation]], or web surfing, is the common practice of following such hyperlinks across multiple websites. [[Web application]]s are web pages that function as [[application software]]. The information in the Web is transferred across the Internet using HTTP. Multiple web resources with a common theme and usually a common [[domain name]] make up a [[website]]. A single web server may provide multiple websites, while some websites, especially the most popular ones, may be provided by multiple servers. Website content is provided by a myriad of companies, organizations, government agencies, and [[User-generated content|individual users]]; and comprises an enormous amount of educational, entertainment, commercial, and government information.

The Web has become the world's dominant [[Web platform|information systems platform]].<ref>{{cite news |last1=Bleigh |first1=Michael |title=The Once And Future Web Platform |url=https://techcrunch.com/2014/05/16/the-once-and-future-web-platform/ |access-date=9 March 2022 |publisher=TechCrunch |date=16 May 2014 |archive-date=5 December 2021 |archive-url=https://web.archive.org/web/20211205122820/https://techcrunch.com/2014/05/16/the-once-and-future-web-platform/ |url-status=live }}</ref><ref>{{cite web |date=11 March 2014 |title=''World Wide Web Timeline'' |url=http://www.pewinternet.org/2014/03/11/world-wide-web-timeline/ |access-date=1 August 2015 |publisher=Pews Research Center |archive-date=29 July 2015 |archive-url=https://web.archive.org/web/20150729162322/http://www.pewinternet.org/2014/03/11/world-wide-web-timeline/ |url-status=live }}</ref><ref>{{cite news |last=Dewey |first=Caitlin |date=12 March 2014 |title=''36 Ways The Web Has Changed Us'' |newspaper=The Washington Post |url=https://www.washingtonpost.com/news/style-blog/wp/2014/03/12/36-ways-the-web-has-changed-us/ |access-date=1 August 2015 |archive-date=9 September 2015 |archive-url=https://web.archive.org/web/20150909195224/https://www.washingtonpost.com/news/style-blog/wp/2014/03/12/36-ways-the-web-has-changed-us/ |url-status=live }}</ref><ref name="internetlivestats"/> It is the primary tool that billions of people worldwide use to interact with the Internet.<ref name="webinternet"/>

== History ==
{{Main|History of the World Wide Web}}
[[File:First_Web_Server.jpg|thumb|This [[NeXT Computer]] was used by [[Sir Tim Berners-Lee]] at [[CERN]] and became the world's first [[Web server]].]]

The Web was invented by English computer scientist [[Tim Berners-Lee]] while working at [[CERN]].<ref name="AHT"/><ref name=samm2016/> He was motivated by the problem of storing, updating, and finding documents and data files in that large and constantly changing organization, as well as distributing them to collaborators outside CERN. In his design, Berners-Lee dismissed the common [[tree (computing)|tree structure]] approach, used for instance in the existing CERNDOC documentation system and in the [[Unix filesystem]], as well as approaches that relied on tagging files with [[Index term|keyword]]s, as in the VAX/NOTES system. Instead he adopted concepts he had put into practice with his private [[ENQUIRE]] system (1980) built at CERN. When he became aware of [[Ted Nelson]]'s [[hypertext]] model (1965), in which documents can be linked in unconstrained ways through [[hyperlink]]s associated with "hot spots" embedded in the text, it helped to confirm the validity of his concept.<ref name=":42">{{Cite thesis |last=Rutter |first=Dorian |title=From Diversity to Convergence: British Computer Networks and the Internet, 1970-1995 |date=2005 |access-date=27 December 2022 |degree=Computer Science |publisher=The University of Warwick |url=http://wrap.warwick.ac.uk/1197/1/WRAP_THESIS_Rutter_2005.pdf |archive-url=https://ghostarchive.org/archive/20221010/http://wrap.warwick.ac.uk/1197/1/WRAP_THESIS_Rutter_2005.pdf |archive-date=10 October 2022 |url-status=live |quote=When Berners-Lee developed his Enquire hypertext system during 1980, the ideas explored by Bush, Engelbart, and Nelson did not influence his work, as he was not aware of them. However, as Berners-Lee began to refine his ideas, the work of these predecessors would later confirm the legitimacy of his system.}}</ref><ref name=":3">{{Cite book |last=Tim Berners-Lee |url=http://archive.org/details/weavingweborigin00bern_0 |title=Weaving the Web |date=1999 |publisher=HarperSanFrancisco |others=Internet Archive |isbn=978-0-06-251586-5 |pages=5–6 |quote=Unbeknownst to me at that early stage in my thinking, several people had hit upon similar concepts, which were never implemented.}}</ref>
[[File:WWW-LetShare.svg|thumb|The historic World Wide Web logo, designed by [[Robert Cailliau]]. Currently, there is no widely accepted logo in use for the WWW.]]
The model was later popularized by [[Apple Computer|Apple]]'s [[HyperCard]] system. Unlike Hypercard, Berners-Lee's new system from the outset was meant to support links between multiple databases on independent computers, and to allow simultaneous access by many users from any computer on the Internet. He also specified that the system should eventually handle other media besides text, such as graphics, speech, and video. Links could refer to  mutable data files, or even fire up programs on their server computer. He also conceived "gateways" that would allow access through the new system to documents organized in other ways (such as traditional computer [[file system]]s or the [[Usenet]]). Finally, he insisted that the system should be decentralized, without any central control or coordination over the creation of links.<ref name="TBL Web Proposal" /><ref name=bern1992>{{Cite journal |last1=Berners-Lee |first1=T. |last2=Cailliau |first2=R. |last3=Groff |first3=J.-F. |last4=Pollermann |first4=B. |date=1992 |title=World-Wide Web: The Information Universe |url=https://www.w3.org/History/1992/ENRAP/Article_9202.ps |journal=Electron. Netw. Res. Appl. Policy |volume=2 |pages=52–58 |doi=10.1108/eb047254 |language=en |access-date=27 December 2022 |archive-date=27 December 2022 |archive-url=https://web.archive.org/web/20221227185345/https://www.w3.org/History/1992/ENRAP/Article_9202.ps |url-status=live |issn = 1066-2243 }}</ref><ref name="AHT">{{cite news |last=Quittner |first=Joshua |date=29 March 1999 |title=Network Designer Tim Berners-Lee |work=Time Magazine |url=http://www.time.com/time/magazine/article/0,9171,990627,00.html |url-status=dead |url-access=subscription |access-date=17 May 2010 |archive-url=https://web.archive.org/web/20070815090521/http://www.time.com/time/magazine/article/0%2C9171%2C990627%2C00.html |archive-date=15 August 2007 |quote=He wove the World Wide Web and created a mass medium for the 21st century. The World Wide Web is Berners-Lee's alone. He designed it. He set it loose it on the world. And he more than anyone else has fought to keep it an open, non-proprietary and free.}}{{page needed|date=September 2016}}</ref><ref name=samm2016>{{cite book |last=McPherson |first=Stephanie Sammartino |url=https://archive.org/details/timbernerslee0000mcph |title=Tim Berners-Lee: Inventor of the World Wide Web |publisher=Twenty-First Century Books |year=2009 |isbn=978-0-8225-7273-2 |url-access=registration}}</ref>

Berners-Lee submitted a proposal to CERN in May 1989, without giving the system a name.<ref name="TBL Web Proposal" /> He got a working system implemented by the end of 1990, including a browser called  [[WorldWideWeb]] (which became the name of the project and of the network) and [[CERN httpd|an HTTP server]] running at CERN. As part of that development he defined the first version of the HTTP protocol, the basic URL syntax, and implicitly made HTML the primary document format.<ref>W3 (1991) [https://www.w3.org/People/Berners-Lee/1991/08/art-6484.txt Re: Qualifiers on Hypertext links] {{Webarchive|url=https://web.archive.org/web/20211207032603/https://www.w3.org/People/Berners-Lee/1991/08/art-6484.txt |date=7 December 2021 }}</ref> The technology was released outside CERN to other research institutions starting in January 1991, and then to the whole Internet on 23 August 1991. The Web was a success at CERN, and began to spread to other scientific and academic institutions. Within the next two years, [[List of websites founded before 1995|there were 50 websites created]].<ref>{{cite web |last1=Hopgood |first1=Bob |title=History of the Web |url=https://www.w3.org/2012/08/history-of-the-web/origins.htm#c7p1 |website=w3.org |publisher=The World Wide Web Consortium |access-date=12 February 2022 |archive-date=21 March 2022 |archive-url=https://web.archive.org/web/20220321090119/https://www.w3.org/2012/08/history-of-the-web/origins.htm#c7p1 |url-status=live }}</ref><ref>{{Cite web |title=A short history of the Web |url=https://home.cern/science/computing/birth-web/short-history-web |access-date=15 April 2022 |website=CERN |language=en |archive-date=17 April 2022 |archive-url=https://web.archive.org/web/20220417082120/https://home.cern/science/computing/birth-web/short-history-web |url-status=live }}</ref>

CERN made the Web protocol and code available royalty free in 1993, enabling its widespread use.<ref>{{cite web |title=Software release of WWW into public domain |url=https://cds.cern.ch/record/1164399/ |access-date=17 February 2022 |website=CERN Document Server |date=30 January 1993 |publisher=CERN |archive-date=17 February 2022 |archive-url=https://web.archive.org/web/20220217212624/https://cds.cern.ch/record/1164399/ |url-status=live }}</ref><ref>{{cite web |date=30 April 2003 |title=Ten Years Public Domain for the Original Web Software |url=http://tenyears-www.web.cern.ch/tenyears-www/Welcome.html |url-status=live |archive-url=https://web.archive.org/web/20090813032723/http://tenyears-www.web.cern.ch/tenyears-www/Welcome.html |archive-date=13 August 2009 |access-date=27 July 2009 |publisher=Tenyears-www.web.cern.ch}}</ref> After the [[National Center for Supercomputing Applications|NCSA]] released the [[Mosaic (web browser)|Mosaic web browser]] later that year, the Web's popularity grew rapidly as [[List of websites founded before 1995|thousands of websites]] sprang up in less than a year.<ref>{{cite magazine |last1=Calore |first1=Michael |title=April 22, 1993: Mosaic Browser Lights Up Web With Color, Creativity |magazine=Wired |url=https://www.wired.com/2010/04/0422mosaic-web-browser/ |access-date=12 February 2022 |date=22 April 2010 |archive-date=24 April 2018 |archive-url=https://web.archive.org/web/20180424075919/https://www.wired.com/2010/04/0422mosaic-web-browser/?mbid=social_twitter_onsiteshare |url-status=live }}</ref><ref name="Couldry">{{cite book |last1=Couldry |first1=Nick |url=https://books.google.com/books?id=AcHvP9trbkAC&pg=PA2 |title=Media, Society, World: Social Theory and Digital Media Practice |date=2012 |publisher=Polity Press |isbn=9780745639208 |location=London |page=2 |access-date=11 December 2020 |archive-date=27 February 2024 |archive-url=https://web.archive.org/web/20240227165043/https://books.google.com/books?id=AcHvP9trbkAC&pg=PA2#v=onepage&q&f=false |url-status=live }}</ref> Mosaic was a graphical browser that could display inline images and submit [[Form (HTML)|forms]] that  were processed by the [[NCSA HTTPd|HTTPd server]].<ref>{{cite web |last1=Hoffman |first1=Jay |title=The Origin of the IMG Tag |url=https://thehistoryoftheweb.com/the-origin-of-the-img-tag/ |access-date=13 February 2022 |website=The History of the Web |date=21 April 1993 |archive-date=13 February 2022 |archive-url=https://web.archive.org/web/20220213213527/https://thehistoryoftheweb.com/the-origin-of-the-img-tag/ |url-status=live }}</ref><ref>{{cite web |last1=Clarke |first1=Roger |title=The Birth of Web Commerce |url=http://www.rogerclarke.com/II/WCBirth.html |access-date=15 February 2022 |website=Roger Clarke's Web-Site |publisher=XAMAX |archive-date=15 February 2022 |archive-url=https://web.archive.org/web/20220215174226/http://www.rogerclarke.com/II/WCBirth.html |url-status=live }}</ref> [[Marc Andreessen]] and [[James H. Clark|Jim Clark]] founded [[Netscape]] the following year and released the [[Netscape Navigator|Navigator browser]], which introduced [[Java (programming language)|Java]] and [[JavaScript]] to the Web. It quickly became the dominant browser. Netscape [[Initial public offering|became a public company]] in 1995 which triggered a frenzy for the Web and started the [[dot-com bubble]].<ref>{{cite web |last1=McCullough |first1=Brian |title=20 YEARS ON: WHY NETSCAPE'S IPO WAS THE "BIG BANG" OF THE INTERNET ERA |url=http://www.internethistorypodcast.com/2015/08/20-years-on-why-netscapes-ipo-was-the-big-bang-of-the-internet-era/ |website=www.internethistorypodcast.com |publisher=INTERNET HISTORY PODCAST |access-date=12 February 2022 |archive-date=12 February 2022 |archive-url=https://web.archive.org/web/20220212213213/http://www.internethistorypodcast.com/2015/08/20-years-on-why-netscapes-ipo-was-the-big-bang-of-the-internet-era/ |url-status=live }}</ref> Microsoft responded by developing its own browser, [[Internet Explorer]], starting the [[browser wars]]. By bundling it with Windows, it became the dominant browser for 14 years.<ref>{{cite magazine |last1=Calore |first1=Michael |title=Sept. 28, 1998: Internet Explorer Leaves Netscape in Its Wake |url=https://www.wired.com/2009/09/0928ie-beats-netscape/ |access-date=14 February 2022 |magazine=Wired |date=28 September 2009 |archive-date=30 November 2021 |archive-url=https://web.archive.org/web/20211130164131/https://www.wired.com/2009/09/0928ie-beats-netscape/ |url-status=live }}</ref>

Berners-Lee founded the [[World Wide Web Consortium]] (W3C) which created [[XML]] in 1996 and recommended replacing HTML with stricter [[XHTML]].<ref>{{cite news |last1=Daly |first1=Janet |title=World Wide Web Consortium Issues XHTML 1.0 as a Recommendation |url=https://www.w3.org/2000/01/xhtml-pressrelease |access-date=8 March 2022 |publisher=W3C |date=26 January 2000 |archive-date=20 June 2021 |archive-url=https://web.archive.org/web/20210620230850/https://www.w3.org/2000/01/xhtml-pressrelease |url-status=live }}</ref> In the meantime, developers began exploiting an IE feature called [[XMLHttpRequest]] to make [[Ajax (programming)|Ajax]] applications and launched the [[Web 2.0]] revolution. [[Mozilla]], [[Opera (company)|Opera]], and Apple rejected XHTML and created the [[WHATWG]] which developed [[HTML5]].<ref>{{cite web |last1=Hickson |first1=Ian |title=WHAT open mailing list announcement |url=https://whatwg.org/news/start |website=whatwg.org |publisher=WHATWG |access-date=16 February 2022 |archive-date=8 March 2022 |archive-url=https://web.archive.org/web/20220308052351/https://whatwg.org/news/start |url-status=live }}</ref> In 2009, the W3C conceded and abandoned XHTML.<ref>{{cite news |last1=Shankland |first1=Stephen |title=An epitaph for the Web standard, XHTML 2 |url=https://www.cnet.com/tech/services-and-software/an-epitaph-for-the-web-standard-xhtml-2/ |access-date=17 February 2022 |publisher=CNet |date=9 July 2009 |archive-date=16 February 2022 |archive-url=https://web.archive.org/web/20220216142629/https://www.cnet.com/tech/services-and-software/an-epitaph-for-the-web-standard-xhtml-2/ |url-status=live }}</ref> In 2019, it ceded control of the HTML specification to the WHATWG.<ref>{{cite web |title=Memorandum of Understanding Between W3C and WHATWG |url=https://www.w3.org/2019/04/WHATWG-W3C-MOU.html |publisher=W3C |access-date=16 February 2022 |archive-date=29 May 2019 |archive-url=https://web.archive.org/web/20190529012854/https://www.w3.org/2019/04/WHATWG-W3C-MOU.html |url-status=live }}</ref>

The World Wide Web has been central to the development of the [[Information Age]] and is the primary tool billions of people use to interact on the [[Internet]].<ref>{{Cite book |last=In |first=Lee |url=https://books.google.com/books?id=wKyeBQAAQBAJ&pg=PA7 |title=Electronic Commerce Management for Business Activities and Global Enterprises: Competitive Advantages: Competitive Advantages |date=30 June 2012 |publisher=IGI Global |isbn=978-1-4666-1801-5 |language=en |access-date=27 September 2020 |archive-date=21 April 2024 |archive-url=https://web.archive.org/web/20240421053156/https://books.google.com/books?id=wKyeBQAAQBAJ&pg=PA7#v=onepage&q&f=false |url-status=live }}</ref><ref>{{Cite book |last=Misiroglu |first=Gina |url=https://books.google.com/books?id=j4KsBwAAQBAJ&pg=PA398 |title=American Countercultures: An Encyclopedia of Nonconformists, Alternative Lifestyles, and Radical Ideas in U.S. History: An Encyclopedia of Nonconformists, Alternative Lifestyles, and Radical Ideas in U.S. History |date=26 March 2015 |publisher=Routledge |isbn=978-1-317-47729-7 |language=en |access-date=27 September 2020 |archive-date=21 April 2024 |archive-url=https://web.archive.org/web/20240421053157/https://books.google.com/books?id=j4KsBwAAQBAJ&pg=PA398#v=onepage&q&f=false |url-status=live }}</ref><ref>{{cite web |date=11 March 2014 |title=World Wide Web Timeline |url=http://www.pewinternet.org/2014/03/11/world-wide-web-timeline |url-status=live |archive-url=https://web.archive.org/web/20150729162322/http://www.pewinternet.org/2014/03/11/world-wide-web-timeline/ |archive-date=29 July 2015 |access-date=1 August 2015 |work=Pew Research Center}}</ref><ref name="internetlivestats">{{cite web |title=Internet Live Stats |url=http://www.internetlivestats.com |url-status=live |archive-url=https://web.archive.org/web/20150702051222/http://www.internetlivestats.com/ |website=internetlivestats.com |archive-date=2 July 2015 |access-date=1 August 2015}}</ref>

== Nomenclature ==
{{more citations needed section|date=August 2023}}
Tim Berners-Lee states that ''World Wide Web'' is officially spelled as three separate words, each capitalised, with no intervening hyphens.<ref>{{cite web |url=https://w3.org/People/Berners-Lee/FAQ.html |title=Frequently asked questions - Spelling of WWW |publisher=W3C |access-date=27 July 2009 |url-status=live |archive-url=https://web.archive.org/web/20090802051415/http://www.w3.org/People/Berners-Lee/FAQ.html |archive-date=2 August 2009}}</ref> Nonetheless, it is often called simply ''the Web'', and also often ''the web''; see [[Capitalization of Internet|Capitalization of ''Internet'']] for details. In Mandarin Chinese, ''World Wide Web'' is commonly translated via a [[phono-semantic matching]] to ''wàn wéi wǎng'' ({{lang|zh|[[wikt:万维网|万维网]]}}), which satisfies ''www'' and literally means "10,000-dimensional net", a translation that reflects the design concept and proliferation of the World Wide Web.

Use of the www prefix has been declining, especially when [[web application]]s sought to brand their domain names and make them easily pronounceable. As the [[mobile web]] grew in popularity,<ref>{{cite web |url=https://www.statista.com/statistics/277125/share-of-website-traffic-coming-from-mobile-devices/ |title=Percentage of mobile device website traffic worldwide from 1st quarter 2015 to 4th quarter 2024 |publisher=Statista |access-date=17 April 2025 |url-status=live}}</ref> services like [[Gmail|Gmail.com]], [[Outlook.com]], [[Myspace]].com, [[Facebook]].com and [[Twitter]].com are most often mentioned without adding "www." (or, indeed, ".com") to the domain.<ref name="cas">{{cite web |last1=Castelluccio |first1=Michael |title=It's not your grandfather's Internet |url=https://www.thefreelibrary.com/It%27s+not+your+grandfather%27s+Internet.-a0239804575 |date=Oct 1, 2010 |work=Strategic Finance |via=The Free Library |publisher=Institute of Management Accountants |access-date=7 February 2016 |archive-date=5 March 2016 |archive-url=https://web.archive.org/web/20160305145947/http://www.thefreelibrary.com/It%27s+not+your+grandfather%27s+Internet.-a0239804575 |url-status=live }}</ref>

In English, ''www'' is usually read as ''double-u double-u double-u''.<ref>{{cite web |title=Audible pronunciation of 'WWW' |url=http://www.oxforddictionaries.com/us/definition/american_english/WWW?q=www |publisher=Oxford University Press |access-date=25 May 2014 |url-status=dead |archive-url=https://web.archive.org/web/20140525195152/http://www.oxforddictionaries.com/us/definition/american_english/WWW?q=www |archive-date=25 May 2014}}</ref> Some users pronounce it ''dub-dub-dub'', particularly in New Zealand.<ref>{{cite web |last1=Harvey |first1=Charlie |title=How we pronounce WWW in English: a detailed but unscientific survey |url=https://charlieharvey.org.uk/page/how_we_pronounce_www |website=charlieharvey.org.uk |date=18 August 2015 |access-date=19 May 2022 |archive-date=19 November 2022 |archive-url=https://web.archive.org/web/20221119073310/https://charlieharvey.org.uk/page/how_we_pronounce_www |url-status=live }}</ref> [[Stephen Fry]], in his "Podgrams" series of podcasts, pronounces it ''wuh wuh wuh''.<ref>{{cite web |title=Stephen Fry's pronunciation of 'WWW' |url=http://www.podcasts.com/stephen_frys_podgrams_audio_visual/episode/series_2_episode_1_stephenfry.com_2.0 |publisher=Podcasts.com |url-status=dead |archive-url=https://web.archive.org/web/20170404220105/http://www.podcasts.com/stephen_frys_podgrams_audio_visual/episode/series_2_episode_1_stephenfry.com_2.0 |archive-date=4 April 2017}}</ref> The English writer [[Douglas Adams]] once quipped in ''[[The Independent]] on Sunday'' (1999): "The World Wide Web is the only thing I know of whose shortened form takes three times longer to say than what it's short for".<ref name="Sim">{{cite web |last1=Simonite |first1=Tom |title=Help us find a better way to pronounce www |url=https://www.newscientist.com/blog/technology/2008/07/help-us-find-better-way-to-pronounce.html |website=newscientist.com |publisher=New Scientist, Technology |date=22 July 2008 |access-date=7 February 2016 |url-status=live |archive-url=https://web.archive.org/web/20160313095715/https://www.newscientist.com/blog/technology/2008/07/help-us-find-better-way-to-pronounce.html |archive-date=13 March 2016}}</ref>

== Function ==
{{main|HTTP|HTML}}
[[File:Internet Key Layers.png|thumb|The World Wide Web functions as an [[application layer]] [[communications protocol|protocol]] that is run "on top of" (figuratively) the Internet, helping to make it more functional. The advent of the [[Mosaic (web browser)|Mosaic]] web browser helped to make the web much more usable, to include the display of images and moving images ([[GIF]]s).]]

The terms ''Internet'' and ''World Wide Web'' are often used without much distinction. However, the two terms do not mean the same thing. The Internet is a global system of [[computer network]]s interconnected through telecommunications and [[optical networking]]. In contrast, the World Wide Web is a global collection of documents and other [[Web resource|resources]], linked by hyperlinks and [[Uniform Resource Identifier|URIs]]. Web resources are accessed using [[HTTP]] or [[HTTPS]], which are application-level Internet protocols that use the Internet transport protocols.<ref name="webinternet"/>

Viewing a [[web page]] on the World Wide Web normally begins either by typing the [[uniform resource locator|URL]] of the page into a web browser or by following a hyperlink to that page or resource. The web browser then initiates a series of background communication messages to fetch and display the requested page. In the 1990s, using a browser to view web pages—and to move from one web page to another through hyperlinks—came to be known as 'browsing,' 'web surfing' (after [[channel surfing]]), or 'navigating the Web'. Early studies of this new behaviour investigated user patterns in using web browsers. One study, for example, found five user patterns: exploratory surfing, window surfing, evolved surfing, bounded navigation and targeted navigation.<ref>{{cite journal|last1=Muylle|first1=Steve|first2=Rudy|last2=Moenaert|first3=Marc|last3=Despont|title=A grounded theory of World Wide Web search behaviour|journal=Journal of Marketing Communications|year=1999|volume=5|issue=3|page=143|doi=10.1080/135272699345644}}</ref>

The following example demonstrates the functioning of a web browser when accessing a page at the URL {{samp|<nowiki>http://example.org/home.html</nowiki>}}. The browser resolves the server name of the URL ({{samp|example.org}}) into an [[IP address|Internet Protocol address]] using the globally distributed [[Domain Name System]] (DNS). This lookup returns an IP address such as ''203.0.113.4'' or ''2001:db8:2e::7334''. The browser then requests the resource by sending an [[Hypertext Transfer Protocol|HTTP]] request across the Internet to the computer at that address. It requests service from a specific TCP port number that is well known for the HTTP service so that the receiving host can distinguish an HTTP request from other network protocols it may be servicing. HTTP normally uses [[List of TCP and UDP port numbers|port number 80]] and for HTTPS it normally uses [[List of TCP and UDP port numbers|port number 443]]. The content of the HTTP request can be as simple as two lines of text:
<syntaxhighlight lang="http">
GET /home.html HTTP/1.1
Host: example.org
</syntaxhighlight>

The computer receiving the HTTP request delivers it to web server software listening for requests on port 80. If the web server can fulfil the request it sends an HTTP response back to the browser indicating success:
<syntaxhighlight lang="http">
HTTP/1.1 200 OK
Content-Type: text/html; charset=UTF-8
</syntaxhighlight>

followed by the content of the requested page. Hypertext Markup Language ([[HTML]]) for a basic web page might look like this:
<syntaxhighlight lang="html">
<html>
  <head>
    <title>Example.org – The World Wide Web</title>
  </head>
  <body>
    <p>The World Wide Web, abbreviated as WWW and commonly known ...</p>
  </body>
</html>
</syntaxhighlight>

The web browser [[parsing|parses]] the HTML and interprets the markup (<syntaxhighlight lang="html" inline><title></syntaxhighlight>, <syntaxhighlight lang="HTML" inline><p></syntaxhighlight> for paragraph, and such) that surrounds the words to format the text on the screen. Many web pages use HTML to reference the URLs of other resources such as images, other embedded media, [[Client-side scripting|scripts]] that affect page behaviour, and [[Cascading Style Sheets]] that affect page layout. The browser makes additional HTTP requests to the web server for these other [[Internet media type]]s. As it receives their content from the web server, the browser progressively [[Browser engine|renders]] the page onto the screen as specified by its HTML and these additional resources.

=== HTML ===
{{main|HTML}}
Hypertext Markup Language (HTML) is the standard [[markup language]] for creating [[web page]]s and [[web application]]s. With [[Cascading Style Sheets]] (CSS) and [[JavaScript]], it forms a triad of [[cornerstone]] technologies for the World Wide Web.<ref>{{cite book|last1=Flanagan|first1=David|title=JavaScript – The definitive guide|page=1|edition=6|quote=JavaScript is part of the triad of technologies that all Web developers must learn: HTML to specify the content of web pages, CSS to specify the presentation of web pages, and JavaScript to specify the behaviour of web pages.}}</ref>

[[Web browser]]s receive HTML documents from a [[web server]] or from local storage and [[browser engine|render]] the documents into multimedia web pages. HTML describes the structure of a web page [[Semantic Web|semantically]] and originally included cues for the appearance of the document.

[[HTML element]]s are the building blocks of HTML pages. With HTML constructs, [[HTML element#Images and objects|images]] and other objects such as [[Fieldset|interactive forms]] may be embedded into the rendered page. HTML provides a means to create [[structured document]]s by denoting structural [[semantics]] for text such as headings, paragraphs, lists, [[Hyperlink|links]], quotes and other items. HTML elements are delineated by ''tags'', written using [[Bracket#Angle brackets|angle brackets]]. Tags such as {{code|lang=html|code=<img />}} and {{code|lang=html|<input />}} directly introduce content into the page. Other tags such as {{code|lang=html|code=<p>}} surround and provide information about document text and may include other tags as sub-elements. Browsers do not display the HTML tags, but use them to interpret the content of the page.

HTML can embed programs written in a [[scripting language]] such as [[JavaScript]], which affects the behaviour and content of web pages. Inclusion of CSS defines the look and layout of content. The [[World Wide Web Consortium]] (W3C), maintainer of both the HTML and the CSS standards, has encouraged the use of CSS over explicit presentational HTML {{as of|1997|lc=y|since=y|post=.}}<ref name="deprecated">{{cite web|url=https://www.w3.org/TR/REC-html40-971218/conform.html#deprecated|title=HTML 4.0 Specification – W3C Recommendation – Conformance: requirements and recommendations|publisher=World Wide Web Consortium|date=18 December 1997|access-date=6 July 2015|archive-date=5 July 2015|archive-url=https://web.archive.org/web/20150705040855/http://www.w3.org/TR/REC-html40-971218/conform.html#deprecated|url-status=live}}</ref>

=== Linking ===
Most web pages contain hyperlinks to other related pages and perhaps to downloadable files, source documents, definitions and other web resources. In the underlying HTML, a hyperlink looks like this:
<syntaxhighlight lang="html" inline=""><a href="http://example.org/home.html">Example.org Homepage</a>.</syntaxhighlight>
[[File:WorldWideWebAroundWikipedia.png|thumb|Graphic representation of a minute fraction of the WWW, demonstrating [[hyperlink]]s]]
Such a collection of useful, related resources, interconnected via hypertext links is dubbed a ''web'' of information. Publication on the Internet created what Tim Berners-Lee first called the ''WorldWideWeb'' (in its original [[CamelCase]], which was subsequently discarded) in November 1990.<ref name="W90">{{cite web |url=http://w3.org/Proposal.html |title=WorldWideWeb: Proposal for a HyperText Project |first1=Tim |last1=Berners-Lee |author-link1=Tim Berners-Lee |first2=Robert |last2=Cailliau |author-link2=Robert Cailliau |date=12 November 1990 |access-date=12 May 2015 |url-status=live|archive-url=https://web.archive.org/web/20150502080527/http://www.w3.org/Proposal.html |archive-date=2 May 2015}}</ref>

The hyperlink structure of the web is described by the [[webgraph]]: the nodes of the web graph correspond to the web pages (or URLs) the directed edges between them to the hyperlinks. Over time, many web resources pointed to by hyperlinks disappear, relocate, or are replaced with different content. This makes hyperlinks obsolete, a phenomenon referred to in some circles as link rot, and the hyperlinks affected by it are often called [[link rot|"dead" links]].<!-- Note: if "dead" isn't in quotes, this page will throw a false positive on template maintenance script runs. --> The ephemeral nature of the Web has prompted many efforts to archive websites. The [[Internet Archive]], active since 1996, is the best known of such efforts.

=== WWW prefix ===
<!-- WWW prefix redirects here -->
Many hostnames used for the World Wide Web begin with ''www'' because of the long-standing practice of naming [[Internet]] hosts according to the services they provide. The [[hostname]] of a [[web server]] is often ''www'', in the same way that it may be ''ftp'' for an [[FTP server]], and ''news'' or ''nntp'' for a [[Usenet]] [[news server]]. These hostnames appear as Domain Name System (DNS) or [[subdomain]] names, as in ''www.example.com''. The use of ''www'' is not required by any technical or policy standard and many websites do not use it; the first web server was ''nxoc01.cern.ch''.<ref>{{cite web |url=http://w3.org/People/Berners-Lee/FAQ.html |title=Frequently asked questions by the Press |first=Tim |last=Berners-Lee |publisher=W3C |access-date=27 July 2009 |url-status=live |archive-url=https://web.archive.org/web/20090802051415/http://www.w3.org/People/Berners-Lee/FAQ.html |archive-date=2 August 2009}}</ref> According to Paolo Palazzi, who worked at CERN along with Tim Berners-Lee, the popular use of ''www'' as subdomain was accidental; the World Wide Web project page was intended to be published at www.cern.ch while info.cern.ch was intended to be the CERN home page; however the DNS records were never switched, and the practice of prepending ''www'' to an institution's website domain name was subsequently copied.<ref>{{cite web |last=Palazzi |first=P |date=2011 |url=http://soft-shake.ch/2011/en/conference/sessions.html?key=earlydays |title=The Early Days of the WWW at CERN |archive-url= https://web.archive.org/web/20120723105704/http://soft-shake.ch/2011/en/conference/sessions.html?key=earlydays |archive-date=23 July 2012 |url-status=dead}}</ref>{{better source needed|date=August 2022}} Many established websites still use the prefix, or they employ other subdomain names such as ''www2'', ''secure'' or ''en'' for special purposes. Many such web servers are set up so that both the main domain name (e.g., example.com) and the ''www'' subdomain (e.g., www.example.com) refer to the same site; others require one form or the other, or they may map to different web sites. The use of a subdomain name is useful for [[load balancing (computing)|load balancing]] incoming web traffic by creating a [[CNAME record]] that points to a cluster of web servers. Since, currently{{As of?|date=September 2023}}, only a subdomain can be used in a CNAME, the same result cannot be achieved by using the bare domain root.<ref>{{cite web |url=https://medium.freecodecamp.org/why-cant-a-domain-s-root-be-a-cname-8cbab38e5f5c |title=Why a domain's root can't be a CNAME – and other tidbits about the DNS |first=Dominic |last=Fraser |date=13 May 2018 |work=FreeCodeCamp |access-date=12 March 2019 |archive-date=21 April 2024 |archive-url=https://web.archive.org/web/20240421053219/https://www.freecodecamp.org/news/why-cant-a-domain-s-root-be-a-cname-8cbab38e5f5c |url-status=live }}</ref>{{Dubious |reason=While CNAMEs are more flexible than the bare domain requiring an A Record, load balancing is certainly possible even for sites that skip www and use the bare domain — see, for example, Twitter.|date=July 2019}}

When a user submits an incomplete domain name to a web browser in its address bar input field, some web browsers automatically try adding the prefix "www" to the beginning of it and possibly ".com", ".org" and ".net" at the end, depending on what might be missing. For example, entering "{{not a typo|microsoft}}" may be transformed to ''<nowiki>http://www.microsoft.com/</nowiki>'' and "openoffice" to ''<nowiki>http://www.openoffice.org</nowiki>''. This feature started appearing in early versions of [[Firefox]], when it still had the working title 'Firebird' in early 2003, from an earlier practice in browsers such as [[Lynx (web browser)|Lynx]].<ref>{{cite web |url=http://forums.mozillazine.org/viewtopic.php?f=9&t=10980 |title=automatically adding www.___.com |publisher=mozillaZine |date=16 May 2003 |access-date=27 May 2009 |url-status=live |archive-url=https://web.archive.org/web/20090627225046/http://forums.mozillazine.org/viewtopic.php?f=9&t=10980 |archive-date=27 June 2009}}</ref> {{unreliable source?|date=November 2016}} It is reported that Microsoft was granted a US patent for the same idea in 2008, but only for mobile devices.<ref>{{cite web |url=http://techdirt.com/articles/20080626/0203581527.shtml |title=Microsoft Patents Adding 'www.' And '.com' To Text |publisher=Techdirt |last=Masnick |first=Mike |date=7 July 2008 |access-date=27 May 2009 |url-status=live |archive-url=https://web.archive.org/web/20090627212151/http://www.techdirt.com/articles/20080626/0203581527.shtml |archive-date=27 June 2009}}</ref>

=== Scheme specifiers ===
The scheme specifiers ''<code><nowiki>http://</nowiki></code>'' and ''<code><nowiki>https://</nowiki></code>'' at the start of a web [[Uniform Resource Identifier|URI]] refer to [[Hypertext Transfer Protocol]] or [[HTTP Secure]], respectively. They specify the communication protocol to use for the request and response. The HTTP protocol is fundamental to the operation of the World Wide Web, and the added encryption layer in HTTPS is essential when browsers send or retrieve confidential data, such as passwords or banking information. Web browsers usually automatically prepend <nowiki>http://</nowiki> to user-entered URIs, if omitted.{{Citation needed|date=May 2025}}

===Pages===
{{main|Web page}}
[[File:Commons.png|thumb|A screenshot of the home page of Wikimedia Commons]]
A ''web page'' (also written as ''webpage'') is a document that is suitable for the World Wide Web and [[web browser]]s. A web browser displays a web page on a [[computer display|monitor]] or [[mobile device]].

The term ''web page'' usually refers to what is visible, but may also refer to the contents of the [[computer file]] itself, which is usually a [[text file]] containing [[hypertext]] written in [[HTML]] or a comparable [[markup language]]. Typical web pages provide [[hypertext]] for browsing to other web pages via [[hyperlink]]s, often referred to as ''links''. Web browsers will frequently have to access multiple [[web resource]] elements, such as reading [[Cascading Style Sheets|style sheets]], [[client-side scripting|scripts]], and images, while presenting each web page.

On a network, a web browser can retrieve a web page from a remote [[web server]]. The web server may restrict access to a private network such as a corporate intranet. The web browser uses the [[Hypertext Transfer Protocol]] (HTTP) to make such requests to the [[web server]].

A [[static web page|''static'' web page]] is delivered exactly as stored, as [[web content]] in the web server's [[file system]]. In contrast, a [[dynamic web page|''dynamic'' web page]] is generated by a [[web application]], usually driven by [[server-side scripting|server-side software]]. Dynamic web pages are used when each user may require completely different information, for example, bank websites, web email etc.

==== Static page ====
{{main|Static web page}}
A ''static web page'' (sometimes called a ''flat page/stationary page'') is a [[web page]] that is delivered to the user exactly as stored, in contrast to [[dynamic web page]]s which are generated by a [[web application]].

Consequently, a static web page displays the same information for all users, from all contexts, subject to modern capabilities of a [[web server]] to [[content negotiation|negotiate]] [[MIME type|content-type]] or language of the document where such versions are available and the server is configured to do so.

==== Dynamic pages ====
{{Main|Dynamic web page|Ajax (programming)}}
[[File:Scheme dynamic page en.svg|thumb|right|500px|Dynamic web page: example of server-side scripting ([[PHP]] and [[MySQL]])]]
A ''server-side dynamic web page'' is a [[web page]] whose construction is controlled by an [[application server]] processing server-side scripts. In server-side scripting, [[Parameter (computer programming)|parameters]] determine how the assembly of every new web page proceeds, including the setting up of more client-side processing.

A ''client-side dynamic web page'' processes the web page using JavaScript running in the browser. JavaScript programs can interact with the document via [[Document Object Model]], or DOM, to query page state and alter it. The same client-side techniques can then dynamically update or change the DOM in the same way.

A dynamic web page is then reloaded by the user or by a [[computer program]] to change some variable content. The updating information could come from the server, or from changes made to that page's DOM. This may or may not truncate the browsing history or create a saved version to go back to, but a ''dynamic web page update'' using [[Ajax (programming)|Ajax]] technologies will neither create a page to go back to nor truncate the [[web browsing history]] forward of the displayed page. Using Ajax technologies the end [[User (computing)|user]] gets ''one dynamic page'' managed as a single page in the [[web browser]] while the actual [[web content]] rendered on that page can vary. The Ajax engine sits only on the browser requesting parts of its DOM, ''the'' DOM, for its client, from an application server.

Dynamic HTML, or DHTML, is the umbrella term for technologies and methods used to create web pages that are not [[static web page]]s, though it has fallen out of common use since the popularization of [[Ajax (programming)|AJAX]], a term which is now itself rarely used.{{citation needed|date=March 2021}} Client-side-scripting, server-side scripting, or a combination of these make for the dynamic web experience in a browser.

[[JavaScript]] is a [[scripting programming language|scripting language]] that was initially developed in 1995 by [[Brendan Eich]], then of [[Netscape]], for use within web pages.<ref name=Hamilton>{{cite web|author=Hamilton, Naomi|title=The A-Z of Programming Languages: JavaScript|url=http://computerworld.com.au/article/255293/-z_programming_languages_javascript|date=31 July 2008|work=Computerworld|publisher=IDG|access-date=12 May 2009|url-status=live|archive-url=https://web.archive.org/web/20090524025720/http://www.computerworld.com.au/article/255293/-z_programming_languages_javascript|archive-date=24 May 2009}}</ref> The standardised version is [[ECMAScript]].<ref name=Hamilton /> To make web pages more interactive, some web applications also use JavaScript techniques such as [[Ajax (programming)|Ajax]] ([[Asynchronous I/O|asynchronous]] JavaScript and [[XML]]). [[Client-side scripting|Client-side script]] is delivered with the page that can make additional HTTP requests to the server, either in response to user actions such as mouse movements or clicks, or based on elapsed time. The server's responses are used to modify the current page rather than creating a new page with each response, so the server needs only to provide limited, incremental information. Multiple Ajax requests can be handled at the same time, and users can interact with the page while data is retrieved. Web pages may also regularly [[polling (computer science)|poll]] the server to check whether new information is available.<ref>{{cite web|url=http://buntin.org/2008/sep/23/jquery-polling-plugin/|title=jQuery Polling plugin|date=23 September 2008|last=Buntin|first=Seth|access-date=22 August 2009|url-status=dead|archive-url=https://web.archive.org/web/20090813184848/http://buntin.org/2008/sep/23/jquery-polling-plugin/|archive-date=13 August 2009}}</ref>

===Website===
[[File:United States Antarctic Program website from 2018 02 22.png|thumb|right|240px|The [[United States Antarctic Program|usap.gov]] website]]
{{main|Website}}
A ''website''<ref>{{cite web|url=http://www.thefreedictionary.com/Website|title=website|website=[[TheFreeDictionary.com]]|access-date=2 July 2011|archive-date=7 May 2018|archive-url=https://web.archive.org/web/20180507204408/https://www.thefreedictionary.com/website|url-status=live}}</ref> is a collection of related web resources including [[web page]]s, [[multimedia]] content, typically identified with a common [[domain name]], and published on at least one [[web server]]. Notable examples are [[wikipedia]].org, [[google]].com, and [[Amazon (company)|amazon.com]].

A website may be accessible via a public [[Internet Protocol]] (IP) network, such as the [[Internet]], or a private [[local area network]] (LAN), by referencing a [[URL|uniform resource locator]] (URL) that identifies the site.

Websites can have many functions and can be used in various fashions; a website can be a [[personal website]], a corporate website for a company, a government website, an organization website, etc. Websites are typically dedicated to a particular topic or purpose, ranging from entertainment and [[social networking]] to providing news and education. All publicly accessible websites collectively constitute the World Wide Web, while private websites, such as a company's website for its employees, are typically a part of an [[intranet]].

Web pages, which are the building blocks of websites, are [[document]]s, typically composed in [[plain text]] interspersed with [[Formatted text|formatting instructions]] of Hypertext Markup Language ([[HTML]], [[XHTML]]). They may incorporate elements from other websites with suitable [[HTML anchor|markup anchors]]. Web pages are accessed and transported with the [[Hypertext Transfer Protocol]] (HTTP), which may optionally employ encryption ([[HTTP Secure]], HTTPS) to provide security and privacy for the user. The user's application, often a [[web browser]], renders the page content according to its HTML markup instructions onto a [[Computer monitor|display terminal]].

[[Hyperlink]]ing between web pages conveys to the reader the [[site map|site structure]] and guides the navigation of the site, which often starts with a [[home page]] containing a directory of the site [[web content]]. Some websites require user registration or [[subscription]] to access content. Examples of [[paywall|subscription websites]] include many business sites, news websites, [[academic journal]] websites, gaming websites, file-sharing websites, [[Internet forum|message boards]], web-based [[email]], [[social networking]] websites, websites providing real-time price quotations for different types of markets, as well as sites providing various other services. [[End user]]s can access websites on a range of devices, including [[desktop computer|desktop]] and [[laptop|laptop computers]], [[tablet computer]]s, [[smartphone]]s and [[smart TV]]s.

===Browser===
{{main|Web browser}}
A ''web browser'' (commonly referred to as a ''browser'') is a [[software application|software]] [[user agent]] for accessing information on the World Wide Web. To connect to a website's [[web server|server]] and display its pages, a user needs to have a web browser program. This is the program that the user runs to download, format, and display a web page on the user's computer.

In addition to allowing users to find, display, and move between web pages, a web browser will usually have features like keeping bookmarks, recording history, managing cookies (see below), and home pages and may have facilities for recording passwords for logging into websites.

The most popular browsers are [[Google Chrome|Chrome]], [[Safari (web browser)|Safari]], [[Microsoft Edge|Edge]], [[Samsung Internet]] and [[Firefox]].<ref>{{Cite web |title=Top Browsers Market Share |url=https://www.similarweb.com/browsers/ |access-date=2025-02-15 |website=www.similarweb.com |archive-date=17 February 2025 |archive-url=https://web.archive.org/web/20250217112440/https://www.similarweb.com/browsers/ |url-status=live }}</ref>

===Server===
{{main|Web server}}

[[File:Inside and Rear of Webserver.jpg|thumb|right|The inside and front of a [[Dell PowerEdge]] web server, a computer designed for [[rack mount]]ing]]
A ''Web server'' is [[server software]], or hardware dedicated to running said software, that can satisfy World Wide Web client requests. A web server can, in general, contain one or more websites. A web server processes incoming network requests over [[Hypertext Transfer Protocol|HTTP]] and several other related protocols.

The primary function of a web server is to store, process and deliver [[web page]]s to [[Client (computing)|clients]].<ref>{{Cite book|title=Web performance tuning|last=Patrick|first=Killelea|date=2002|publisher=O'Reilly|isbn=978-0596001728|edition= 2nd|location=Beijing|pages=264|oclc=49502686}}</ref> The communication between client and server takes place using the [[Hypertext Transfer Protocol|Hypertext Transfer Protocol (HTTP)]]. Pages delivered are most frequently [[HTML|HTML documents]], which may include [[image]]s, [[Style sheet (web development)|style sheets]] and [[JavaScript|scripts]] in addition to the text content.
[[File:Wikimedia Foundation Servers-8055 35.jpg|thumb|275x275px|Multiple web servers may be used for a high traffic website; here, [[Dell]] servers are installed together to be used for the [[Wikimedia Foundation]].]]

A [[user agent]], commonly a [[web browser]] or [[web crawler]], initiates communication by making a [[Hypertext Transfer Protocol#Request message|request]] for a specific resource using HTTP and the server responds with the content of that resource or an [[List of HTTP status codes#4xx client errors|error message]] if unable to do so. The resource is typically a real file on the server's [[secondary memory|secondary storage]], but this is not necessarily the case and depends on how the webserver is [[Implementation|implemented]].

While the primary function is to serve content, full implementation of HTTP also includes ways of receiving content from clients. This feature is used for submitting [[Form (web)|web forms]], including [[upload]]ing of files.

Many generic web servers also support  [[server-side scripting|scripting]] using [[Active Server Pages]] (ASP), [[PHP]] (Hypertext Preprocessor), or other [[scripting language]]s. This means that the behaviour of the webserver can be scripted in separate files, while the actual server software remains unchanged. Usually, this function is used to generate HTML documents [[Dynamic web page|dynamically]] ("on-the-fly") as opposed to returning [[Static web page|static documents]]. The former is primarily used for retrieving or modifying information from [[database]]s. The latter is typically much faster and more easily [[web cache|cached]] but cannot deliver [[dynamic content]].

Web servers can also frequently be found [[embedded system|embedded]] in devices such as [[printer (computing)|printers]], [[Router (computing)|routers]], [[webcam]]s and serving only a [[Local area network|local network]]. The web server may then be used as a part of a system for monitoring or administering the device in question. This usually means that no additional software has to be installed on the client computer since only a web browser is required (which now is included with most [[operating system]]s).

===Optical Networking===
[[Optical networking]] is a sophisticated infrastructure that utilizes optical fiber to transmit data over long distances, connecting countries, cities, and even private residences. The technology uses optical microsystems like [[tunable laser]]s, filters, [[Attenuator (electronics)|attenuators]], switches, and wavelength-selective switches to manage and operate these networks.<ref>{{Cite journal |last=Liu |first=Xiang |date=2019-12-20 |title=Evolution of Fiber-Optic Transmission and Networking toward the 5G Era |journal=iScience |language=English |volume=22 |pages=489–506 |doi=10.1016/j.isci.2019.11.026 |issn=2589-0042 |pmc=6920305 |pmid=31838439|bibcode=2019iSci...22..489L }}</ref><ref>{{Citation |last=Marom |first=Dan M. |title=3.07 - Optical Communications |date=2008-01-01 |work=Comprehensive Microsystems |pages=219–265 |editor-last=Gianchandani |editor-first=Yogesh B. |url=https://linkinghub.elsevier.com/retrieve/pii/B9780444521903000355 |access-date=2025-01-17 |place=Oxford |publisher=Elsevier |doi=10.1016/b978-044452190-3.00035-5 |isbn=978-0-444-52190-3 |editor2-last=Tabata |editor2-first=Osamu |editor3-last=Zappe |editor3-first=Hans |archive-date=23 January 2025 |archive-url=https://web.archive.org/web/20250123163122/https://linkinghub.elsevier.com/retrieve/pii/B9780444521903000355 |url-status=live }}</ref>

The large quantity of optical fiber installed throughout the world at the end of the twentieth century set the foundation of the Internet as it is used today. The information highway relies heavily on optical networking, a method of sending messages encoded in light to relay information in various telecommunication networks.<ref>{{Cite book |last=Chadha |first=Devi |title=Optical WDM networks: from static to elastic networks |date=2019 |publisher=Wiley-IEEE Press |isbn=978-1-119-39326-9 |location=Hoboken, NJ}}</ref>

The [[ARPANET|Advanced Research Projects Agency Network]] (ARPANET) was one of the first iterations of the Internet, created in collaboration with universities and researchers 1969.<ref>{{Cite web |date=2019-03-29 |title=The Computer History Museum, SRI International, and BBN Celebrate the 40th Anniversary of First ARPANET Transmission, Precursor to Today's Internet {{!}} SRI International |url=https://www.sri.com/newsroom/press-releases/computer-history-museum-sri-international-and-bbn-celebrate-40th-anniversary |access-date=2025-01-21 |archive-url=https://web.archive.org/web/20190329134941/https://www.sri.com/newsroom/press-releases/computer-history-museum-sri-international-and-bbn-celebrate-40th-anniversary |archive-date=29 March 2019 |url-status=dead }}</ref><ref>{{Cite news |last=Markoff |first=John |date=1993-01-24 |title=Building the Electronic Superhighway |url=https://www.nytimes.com/1993/01/24/business/building-the-electronic-superhighway.html |access-date=2025-01-21 |work=The New York Times |language=en-US |issn=0362-4331}}</ref><ref>{{Cite book |last=Abbate |first=Janet |title=Inventing the Internet |date=2000 |publisher=MIT Press |isbn=978-0-262-51115-5 |edition=3rd printing |series=Inside technology |location=Cambridge, Mass.}}</ref><ref name=":0">{{Cite web |title=NSFNET: A Partnership for High-Speed Networking |url=http://www.merit.edu/wp-content/uploads/2019/06/NSFNET_final-1.pdf |archive-url=https://web.archive.org/web/20241106150721/https://www.merit.edu/wp-content/uploads/2019/06/NSFNET_final-1.pdf |archive-date=6 November 2024 |access-date=2025-01-21 |website=www.merit.edu |url-status=live }}</ref> However, access to the ARPANET was limited to researchers, and in 1985, the [[National Science Foundation]] founded the [[National Science Foundation Network]] (NSFNET), a program that provided supercomputer access to researchers.<ref name=":0" />

Limited public access to the Internet led to pressure from consumers and corporations to privatize the network. In 1993, the US passed the [[National Information Infrastructure|National Information Infrastructure Act]], which dictated that the National Science Foundation must hand over control of the optical capabilities to commercial operators.<ref>{{Cite web |last=Rep. Boucher |first=Rick [D-VA-9 |date=1993-09-14 |title=H.R.1757 - 103rd Congress (1993-1994): National Information Infrastructure Act of 1993 |url=https://www.congress.gov/bill/103rd-congress/house-bill/1757 |access-date=2025-01-23 |website=www.congress.gov |archive-date=10 November 2021 |archive-url=https://web.archive.org/web/20211110001120/https://www.congress.gov/bill/103rd-congress/house-bill/1757 |url-status=live }}</ref><ref>{{Cite web |date=2003-07-25 |title=NSF Shapes the Internet's Evolution {{!}} NSF - National Science Foundation |url=https://new.nsf.gov/news/nsf-shapes-internets-evolution |access-date=2025-01-23 |website=new.nsf.gov |language=en}}</ref>

The privatization of the Internet and the release of the World Wide Web to the public in 1993 led to an increased demand for Internet capabilities. This spurred developers to seek solutions to reduce the time and cost of laying new fiber and increase the amount of information that can be sent on a single fiber, in order to meet the growing needs of the public.<ref>{{Citation |last=Radu |first=Roxana |title=Privatization and Globalization of the Internet |date=2019-03-07 |work=Negotiating Internet Governance |pages=75–112 |editor-last=Radu |editor-first=Roxana |url=https://academic.oup.com/book/35243/chapter/299787096 |access-date=2025-01-23 |publisher=Oxford University Press |doi=10.1093/oso/9780198833079.003.0004 |isbn=978-0-19-883307-9 |archive-date=14 February 2025 |archive-url=https://web.archive.org/web/20250214121234/https://academic.oup.com/book/35243/chapter/299787096 |url-status=live }}</ref><ref>{{Cite web |title=Birth of the Commercial Internet - NSF Impacts {{!}} NSF - National Science Foundation |url=https://new.nsf.gov/impacts/internet#:~:text=Going%20public,dedicated%20infrastructure%20backbone%20in%201995 |access-date=2025-01-23 |website=new.nsf.gov |language=en}}</ref><ref>{{Cite news |last=Markoff |first=John |date=1997-03-03 |title=Fiber-Optic Technology Draws Record Stock Value |url=https://www.nytimes.com/1997/03/03/business/fiber-optic-technology-draws-record-stock-value.html |access-date=2025-01-23 |work=The New York Times |language=en-US |issn=0362-4331 |archive-date=9 October 2019 |archive-url=https://web.archive.org/web/20191009170252/https://www.nytimes.com/1997/03/03/business/fiber-optic-technology-draws-record-stock-value.html |url-status=live }}</ref><ref>Paul Korzeniowski, [https://www.proquest.com/trade-journals/record-growth-spurs-demand-dense-wdm/docview/226891627/se-2?accountid=44910 “Record Growth Spurs Demand for Dense WDM -- Infrastructure Bandwidth Gears up for next Wave,”] CommunicationsWeek, no. 666 (June 2, 1997): T.40.</ref>

In 1994, Pirelli S.p.A.'s optical components division introduced a wavelength-division multiplexing (WDM) system to meet growing demand for increased data transmission. This four-channel WDM technology allowed more information to be sent simultaneously over a single optical fiber, effectively boosting network capacity.<ref>{{Cite book |last=Hecht |first=Jeff |title=City of light: the story of fiber optics |date=1999 |publisher=Oxford University Press |isbn=978-0-19-510818-7 |series=The Sloan technology series |location=New York}}</ref><ref>{{Cite web |title=Cisco to Acquire Pirelli DWDM Unit for $2.15 Billion |url=https://www.fiberopticsonline.com/doc/cisco-to-acquire-pirelli-dwdm-unit-for-215-bi-0001 |access-date=2025-01-31 |website=www.fiberopticsonline.com}}</ref>

Pirelli wasn't the only company that developed a WDM system; another company, the [[Ciena|Ciena Corporation]] (Ciena), created its own technology to transmit data more efficiently. [[David R. Huber|David Huber]], an optical networking engineer and entrepreneur [[Kevin Kimberlin]] founded Ciena in 1992.<ref>Hirsch, Stacey (February 2, 2006). "Huber steps down as CEO of Broadwing". The Baltimore Sun.</ref><ref>{{Cite web |title=Dr. David Huber |url=https://internethistory.org/bio/dr-david-huber/ |access-date=2025-02-03 |website=History of the Internet |language=en-US}}</ref><ref>{{Cite web |title=Internet Commercialization History |url=https://internethistory.org/commercialization/ |access-date=2025-02-03 |website=History of the Internet |language=en-US}}</ref> Drawing on laser technology from [[Gordon Gould]] and William Culver of [[Optelecom|Optelecom, Inc.]], the company focused on utilizing optical amplifiers to transmit data via light.<ref>{{Cite web |title=May 17, 1993, page 76 - The Baltimore Sun at Baltimore Sun |url=https://baltimoresun.newspapers.com/article/the-baltimore-sun-the-sun-business/170638608/ |access-date=2025-02-03 |website=Newspapers.com |language=en |archive-date=21 February 2025 |archive-url=https://web.archive.org/web/20250221021809/https://baltimoresun.newspapers.com/image/170916535/ |url-status=live }}</ref><ref>Hall, Carla. [http://www.latimes.com/archives/la-xpm-1987-12-17-vw-29544-story.html “Inventor Beams over Laser Patents : After 30 Years, Gordon Gould Gets Credit He Deserves.”] Los Angeles Times, Los Angeles Times, 17 Dec. 1987.</ref><ref>{{Cite news |last=Chang |first=Kenneth |date=2005-09-20 |title=Gordon Gould, 85, Figure in Invention of the Laser, Dies |url=https://www.nytimes.com/2005/09/20/science/gordon-gould-85-figure-in-invention-of-the-laser-dies.html |access-date=2025-02-03 |work=The New York Times |language=en-US |issn=0362-4331 |archive-date=19 September 2017 |archive-url=https://web.archive.org/web/20170919230151/http://www.nytimes.com/2005/09/20/science/gordon-gould-85-figure-in-invention-of-the-laser-dies.html |url-status=live }}</ref> Under chief executive officer Pat Nettles, Ciena developed a dual-stage optical amplifier for dense wavelength-division multiplexing (DWDM), patented in 1997 and deployed on the Sprint network in 1996.<ref>{{Cite web |last=Carroll |first=Jim |date=2024-12-12 |title=Patrick Nettles Steps Down as Executive Chair of Ciena |url=https://convergedigest.com/patrick-nettles-steps-down-as-executive-chair-of-ciena/ |access-date=2025-02-03 |website=Converge Digest |language=en-US |archive-date=14 February 2025 |archive-url=https://web.archive.org/web/20250214112552/https://convergedigest.com/patrick-nettles-steps-down-as-executive-chair-of-ciena/ |url-status=live }}</ref><ref>{{Cite patent|number=US5696615A|title=Wavelength division multiplexed optical communication systems employing uniform gain optical amplifiers|gdate=1997-12-09|invent1=Alexander|inventor1-first=Stephen B.|url=https://patents.google.com/patent/US5696615A/en}}</ref><ref>{{Cite book |last=Hecht |first=Jeff |title=City of light: the story of fiber optics |date=2004 |publisher=Oxford Univ. Press |isbn=978-0-19-510818-7 |edition=Rev. and expanded ed., 1. paperback [ed.] |series=The Sloan technology series |location=Oxford}}</ref><ref>{{Cite web |title=Optica Publishing Group |url=https://opg.optica.org/oe/viewmedia.cfm?uri=oe-26-18-24190&html=true |access-date=2025-02-03 |website=opg.optica.org |archive-date=26 January 2025 |archive-url=https://web.archive.org/web/20250126182827/https://opg.optica.org/oe/viewmedia.cfm?uri=oe-26-18-24190&html=true |url-status=live }}</ref><ref>{{Cite web |title=Sprint boots some users off 'Net - ProQuest |url=https://www.proquest.com/docview/215944575 |access-date=2025-02-03 |website=www.proquest.com | id={{ProQuest|215944575}} |language=en}}</ref>

===Cookie===
{{main|HTTP cookie}}
An ''HTTP cookie'' (also called ''web cookie'', ''Internet cookie'', ''browser cookie'', or simply ''cookie'') is a small piece of data sent from a website and stored on the user's computer by the user's [[web browser]] while the user is browsing. Cookies were designed to be a reliable mechanism for websites to remember [[program state|stateful]] information (such as items added in the shopping cart in an online store) or to record the user's browsing activity (including clicking particular buttons, [[access control|logging in]], or recording which pages were visited in the past). They can also be used to remember arbitrary pieces of information that the user previously entered into form fields such as names, addresses, passwords, and credit card numbers.

Cookies perform essential functions in the modern web. Perhaps most importantly, ''authentication cookies'' are the most common method used by web servers to know whether the user is logged in or not, and which account they are logged in with. Without such a mechanism, the site would not know whether to send a page containing sensitive information or require the user to authenticate themselves by logging in. The security of an authentication cookie generally depends on the security of the issuing website and the user's [[comparison of web browsers#Vulnerabilities|web browser]], and on whether the cookie data is encrypted. Security vulnerabilities may allow a cookie's data to be read by a [[hacker (computer security)|hacker]], used to gain access to user data, or used to gain access (with the user's credentials) to the website to which the cookie belongs (see [[cross-site scripting]] and [[cross-site request forgery]] for examples).<ref>{{cite web |url=http://news.cnet.com/8301-10789_3-9918582-57.html |first=Robert |last=Vamosi |title=Gmail cookie stolen via Google Spreadsheets |website=News.cnet.com |date=14 April 2008 |access-date=19 October 2017 |archive-date=9 December 2013 |archive-url=https://web.archive.org/web/20131209210402/http://news.cnet.com/8301-10789_3-9918582-57.html |url-status=dead }}</ref>

Tracking cookies, and especially third-party tracking cookies, are commonly used as ways to compile long-term records of individuals' browsing histories {{En dash}} a potential [[Internet privacy#HTTP cookies|privacy concern]] that prompted European<ref>{{cite web |title=What about the "EU Cookie Directive"? |url=http://webcookies.org/faq/#Directive |year=2013 |publisher=WebCookies.org |access-date=19 October 2017 |archive-date=11 October 2017 |archive-url=https://web.archive.org/web/20171011095259/https://webcookies.org/faq/#Directive |url-status=dead }}</ref> and U.S. lawmakers to take action in 2011.<ref name="eulaw">{{cite news |url=https://www.bbc.co.uk/news/technology-12668552 |work=BBC |title=New net rules set to make cookies crumble |date=8 March 2011 |access-date=18 February 2019 |archive-date=10 August 2018 |archive-url=https://web.archive.org/web/20180810220427/https://www.bbc.co.uk/news/technology-12668552 |url-status=live }}</ref><ref>{{cite web |url=http://adage.com/article/digital/sen-rockefeller-ready-a-real-track-bill/227426/ |work=Adage.com |title=Sen. Rockefeller: Get Ready for a Real Do-Not-Track Bill for Online Advertising |date=6 May 2011 |access-date=18 February 2019 |archive-date=24 August 2011 |archive-url=https://web.archive.org/web/20110824225528/http://adage.com/article/digital/sen-rockefeller-ready-a-real-track-bill/227426/ |url-status=live }}</ref> European law requires that all websites targeting [[European Union]] member states gain "informed consent" from users before storing non-essential cookies on their device.

Google [[Project Zero (Google)|Project Zero]] researcher Jann Horn describes ways cookies can be read by [[Man-in-the-middle attack|intermediaries]], like [[Wi-Fi]] hotspot providers. When in such circumstances, he recommends using the browser in [[private browsing]] mode (widely known as [[Incognito mode]] in Google Chrome).<ref>[https://thejh.net/written-stuff/want-to-use-my-wifi? Want to use my wifi?] {{Webarchive|url=https://web.archive.org/web/20180104070103/https://thejh.net/written-stuff/want-to-use-my-wifi |date=4 January 2018 }}, Jann Horn accessed 5 January 2018.</ref>

===Search engine===
{{main|Search engine}}
[[File:Mayflower Wikimedia Commons image search engine screenshot.png|thumb|upright=1.35|The results of a search for the term "lunar eclipse" in a web-based [[image search]] engine]]
A ''web search engine'' or ''Internet search engine'' is a [[software system]] that is designed to carry out ''web search'' (''Internet search''), which means to search the World Wide Web in a systematic way for particular information specified in a [[web search query]]. The search results are generally presented in a line of results, often referred to as [[search engine results page]]s (SERPs). The information may be a mix of [[web page]]s, images, videos, infographics, articles, research papers, and other types of files. Some search engines also [[data mining|mine data]] available in [[database]]s or [[web directory|open directories]]. Unlike [[web directories]], which are maintained only by human editors, search engines also maintain [[real-time computing|real-time]] information by running an [[algorithm]] on a [[web crawler]]. Internet content that is not capable of being searched by a web search engine is generally described as the [[deep web]].

In 1990, [[Archie (search engine)|Archie]], the world's first search engine, was released. The technology was originally an index of [[File Transfer Protocol]] (FTP) sites, which was a method for moving files between a client and a server network.<ref>{{Cite web |last=Nguyen |first=Jennimai |date=2020-09-10 |title=Archie, the very first search engine, was released 30 years ago today |url=https://mashable.com/article/first-search-engine-archie?test_uuid=01iI2GpryXngy77uIpA3Y4B&test_variant=b |access-date=2025-02-04 |website=Mashable |language=en}}</ref><ref>{{Cite web |title=What is File Transfer Protocol (FTP) meaning |url=https://www.fortinet.com/resources/cyberglossary/file-transfer-protocol-ftp-meaning |access-date=2025-02-04 |website=Fortinet |language=en |archive-date=26 January 2025 |archive-url=https://web.archive.org/web/20250126193905/https://www.fortinet.com/resources/cyberglossary/file-transfer-protocol-ftp-meaning |url-status=live }}</ref> This early search tool was superseded by more advanced engines like [[Yahoo!]] in 1995 and [[Google Search|Google]] in 1998.<ref>{{Cite web |date=2025-02-04 |title=Britannica Money |url=https://money.britannica.com/money/Google-Inc |access-date=2025-02-04 |website=www.britannica.com |language=en |archive-date=27 July 2024 |archive-url=https://web.archive.org/web/20240727122207/https://money.britannica.com/money/Google-Inc |url-status=live }}</ref><ref>{{Cite news |last=Clark |first=Andrew |date=2008-02-01 |title=How Jerry's guide to the world wide web became Yahoo |url=https://www.theguardian.com/business/2008/feb/01/microsoft.technology |access-date=2025-02-04 |work=The Guardian |language=en-GB |issn=0261-3077 |archive-date=5 October 2013 |archive-url=https://web.archive.org/web/20131005052548/http://www.theguardian.com/business/2008/feb/01/microsoft.technology |url-status=live }}</ref>

===Deep web===
{{Multiple image
| image1            = Deep web diagram.png
| caption1          = Deep web diagram
| width1            = 1400
| image2            = Deep web vs surface web.svg
| caption2          = Deep web vs surface web
| width2            = 1400
| image3            = Surface Web & Deep Web.jpg
| width3            = 1400
| caption3          = Surface Web & Deep Web
| total_width       = 230
| direction         = vertical
}}
{{main|Deep web}}
The deep web,<ref name="nhamilton">{{cite journal|url=https://www.iadisportal.org/digital-library/the-mechanics-of-a-deep-net-metasearch-engine|journal=IADIS Digital Library|title=The Mechanics of a Deep Net Metasearch Engine|last=Hamilton|first=Nigel|date=13 May 2024|pages=1034–1036|isbn=978-972-98947-0-1|archive-date=31 May 2023|access-date=6 May 2024|archive-url=https://web.archive.org/web/20230531071443/https://www.iadisportal.org/digital-library/the-mechanics-of-a-deep-net-metasearch-engine|url-status=live}}</ref> ''invisible web'',<ref name="jal">{{cite journal|title=Beyond google: the invisible web in the academic library |volume=30|issue=4|date=July 2004|pages=265–269|last1=Devine|first1=Jane|last2=Egger-Sider|first2=Francine|journal=The Journal of Academic Librarianship |doi=10.1016/j.acalib.2004.04.010 }}</ref> or ''hidden web''<ref name="cthw">{{cite journal|title=Crawling the Hidden Web|journal=27th International Conference on Very Large Data Bases|date=11–14 September 2001|first1=Sriram|last1=Raghavan|first2=Hector|last2=Garcia-Molina|url=http://ilpubs.stanford.edu:8090/725/|access-date=18 February 2019|archive-date=17 August 2019|archive-url=https://web.archive.org/web/20190817174115/http://ilpubs.stanford.edu:8090/725/|url-status=live}}</ref> are parts of the World Wide Web whose contents are not [[Search engine indexing|indexed]] by standard [[web search engine]]s. The opposite term to the deep web is the [[surface web]], which is accessible to anyone using the Internet.<ref>{{cite web |title=Surface Web |url=https://www.computerhope.com/jargon/s/surface-web.htm |publisher=Computer Hope |access-date=20 June 2018 |archive-date=5 May 2020 |archive-url=https://web.archive.org/web/20200505062819/https://www.computerhope.com/jargon/s/surface-web.htm |url-status=live }}</ref> [[Computer scientist]] Michael K. Bergman is credited with coining the term ''deep web'' in 2001 as a search indexing term.<ref name="wright2009"/>

The content of the deep web is hidden behind [[HTTP]] forms,<ref>Madhavan, J., Ko, D., Kot, Ł., Ganapathy, V., Rasmussen, A., & Halevy, A. (2008). Google's deep web crawl. Proceedings of the VLDB Endowment, 1(2), 1241–52.</ref><ref>{{cite web|url=https://www.questia.com/article/1G1-370513892/how-do-you-want-me-to-do-it-does-it-have-to-look|title=How Do You Want Me to Do It? Does It Have to Look like an Accident? – an Assassin Selling a Hit on the Net; Revealed Inside the Deep Web|url-access=subscription|via=|newspaper=[[Sunday Mail (Scotland)|Sunday Mail]]|date=8 June 2014|first=Sam|last=Shedden|access-date=5 May 2017|archive-date=1 March 2020|archive-url=https://web.archive.org/web/20200301174912/https://www.questia.com/article/1G1-370513892/how-do-you-want-me-to-do-it-does-it-have-to-look|url-status=dead}}</ref> and includes many very common uses such as [[web mail]], [[online banking]], and services that users must pay for, and which is protected by a [[paywall]], such as [[video on demand]], some online magazines and newspapers, among others.

The content of the deep web can be located and accessed by a direct [[URL]] or [[IP address]] and may require a password or other security access past the public website page.

=== Caching ===
A [[web cache]] is a server computer located either on the public Internet or within an enterprise that stores recently accessed web pages to improve response time for users when the same content is requested within a certain time after the original request. Most web browsers also implement a [[browser cache]] by writing recently obtained data to a local data storage device. HTTP requests by a browser may ask only for data that has changed since the last access. Web pages and resources may contain expiration information to control caching to secure sensitive data, such as in [[online banking]], or to facilitate frequently updated sites, such as news media. Even sites with highly dynamic content may permit basic resources to be refreshed only occasionally. Web site designers find it worthwhile to collate resources such as CSS data and JavaScript into a few site-wide files so that they can be cached efficiently. Enterprise [[Firewall (networking)|firewalls]] often cache Web resources requested by one user for the benefit of many users. Some [[search engines]] store cached content of frequently accessed websites.

== Security ==
For [[criminal]]s, the Web has become a venue to spread [[malware]] and engage in a range of [[cybercrime]], including (but not limited to) [[identity theft]], [[fraud]], [[espionage]], and [[intelligence gathering]].<ref name=Ben-Itzhak /> Web-based [[vulnerability (computing)|vulnerabilities]] now outnumber traditional computer security concerns,<ref>{{cite web|author1=Christey, Steve|author2=Martin, Robert A.|name-list-style=amp|title=Vulnerability Type Distributions in CVE (version 1.1)|url=http://cwe.mitre.org/documents/vuln-trends/index.html|date=22 May 2007|publisher=[[MITRE Corporation]]|access-date=7 June 2008|url-status=live|archive-url=https://web.archive.org/web/20130317191715/http://cwe.mitre.org/documents/vuln-trends/index.html|archive-date=17 March 2013}}</ref><ref>{{Cite journal|title=Symantec Internet Security Threat Report: Trends for July–December 2007 (Executive Summary)|publisher=Symantec Corp.|journal=Symantec Internet Security Threat Report|volume=XIII|pages=1–2|date=April 2008|url=http://eval.symantec.com/mktginfo/enterprise/white_papers/b-whitepaper_exec_summary_internet_security_threat_report_xiii_04-2008.en-us.pdf|access-date=11 May 2008|url-status=dead|archive-url=https://web.archive.org/web/20080625065121/http://eval.symantec.com/mktginfo/enterprise/white_papers/b-whitepaper_exec_summary_internet_security_threat_report_xiii_04-2008.en-us.pdf|archive-date=25 June 2008}}</ref> and as measured by [[Google]], about one in ten web pages may contain malicious code.<ref>{{cite news|title=Google searches web's dark side|url=http://news.bbc.co.uk/2/hi/technology/6645895.stm|date=11 May 2007|work=BBC News|access-date=26 April 2008|url-status=live|archive-url=https://web.archive.org/web/20080307211615/http://news.bbc.co.uk/2/hi/technology/6645895.stm|archive-date=7 March 2008}}</ref> Most web-based [[attack (computing)|attacks]] take place on legitimate websites, and most, as measured by [[Sophos]], are hosted in the United States, China and Russia.<ref name=Sophos-Q1-2008>{{cite web|title=Security Threat Report (Q1 2008)|url=http://www.sophos.com/sophos/docs/eng/marketing_material/sophos-threat-report-Q108.pdf|publisher=Sophos|access-date=24 April 2008|url-status=live|archive-url=https://web.archive.org/web/20131231084932/http://www.sophos.com/en-us/support/documentation.aspx?requested=eng%2Fmarketing_material%2Fsophos-threat-report-Q108.pdf|archive-date=31 December 2013}}</ref> The most common of all malware [[Threat (computer)|threats]] is [[SQL injection]] attacks against websites.<ref>{{cite web|title=Security threat report|url=http://www.sophos.com/sophos/docs/eng/papers/sophos-security-report-jul08-srna.pdf|date=July 2008|publisher=Sophos|access-date=24 August 2008|url-status=live|archive-url=https://web.archive.org/web/20131231084007/http://www.sophos.com/en-us/medialibrary/gated%20assets/white%20papers/sophossecurityreportjul08srna.pdf|archive-date=31 December 2013}}</ref> Through HTML and URIs, the Web was vulnerable to attacks like [[cross-site scripting]] (XSS) that came with the introduction of JavaScript<ref name=FGHR>{{Cite book|author1=Jeremiah Grossman|author2=Robert "RSnake" Hansen|author3=Petko "pdp" D. Petkov|author4=Anton Rager|author5=Seth Fogie|title=Cross Site Scripting Attacks: XSS Exploits and Defense|pages=68–69, 127|publisher=Syngress, Elsevier Science & Technology|url=https://theswissbay.ch/pdf/Gentoomen%20Library/Security/Cross%20Site%20Scripting%20Attacks%20Xss%20Exploits%20and%20Defense.pdf|archive-url=https://web.archive.org/web/20241115013526/https://theswissbay.ch/pdf/Gentoomen%20Library/Security/Cross%20Site%20Scripting%20Attacks%20Xss%20Exploits%20and%20Defense.pdf|archive-date=15 November 2024|year=2007|isbn=978-1-59749-154-9|access-date=23 January 2025|url-status=live}}</ref> and were exacerbated to some degree by [[Web 2.0]] and Ajax [[web design]] that favours the use of scripts.<ref>{{cite web |author=O'Reilly, Tim |date=30 September 2005 |title=What Is Web 2.0 |url=http://www.oreillynet.com/pub/a/oreilly/tim/news/2005/09/30/what-is-web-20.html |url-status=live |archive-url=https://archive.today/20120628212146/http://www.oreillynet.com/pub/a/oreilly/tim/news/2005/09/30/what-is-web-20.html |archive-date=2012-06-28 |access-date=4 June 2008 |publisher=O'Reilly Media |pages=4–5}} and AJAX web applications can introduce security vulnerabilities like "client-side security controls, increased attack surfaces, and new possibilities for Cross-Site Scripting (XSS)", in {{Cite journal |author=Ritchie, Paul |date=March 2007 |title=The security risks of AJAX/web 2.0 applications |url=http://www.infosecurity-magazine.com/research/Sep07_Ajax.pdf |journal=Infosecurity |archive-url=https://web.archive.org/web/20080625065122/http://www.infosecurity-magazine.com/research/Sep07_Ajax.pdf |archive-date=25 June 2008 |access-date=6 June 2008}} which cites {{Cite news |author1=Hayre, Jaswinder S. |author2=Kelath, Jayasankar |name-list-style=amp |date=22 June 2006 |title=Ajax Security Basics |publisher=SecurityFocus |url=http://www.securityfocus.com/infocus/1868 |url-status=live |access-date=6 June 2008 |archive-url=https://web.archive.org/web/20080515114747/http://www.securityfocus.com/infocus/1868 |archive-date=15 May 2008}}</ref> In one 2007 estimate, 70% of all websites are open to XSS attacks on their users.<ref>{{Cite news|author=Berinato, Scott|title=Software Vulnerability Disclosure: The Chilling Effect|url=http://www.csoonline.com/article/221113|archive-url=https://web.archive.org/web/20080418072230/http://www.csoonline.com/article/221113|archive-date=18 April 2008|work=CSO|page=7|publisher=[[CXO Media]]|date=1 January 2007|access-date=7 June 2008}}</ref> [[Phishing]] is another common threat to the Web. In February 2013, RSA (the security division of EMC) estimated the global losses from phishing at $1.5&nbsp;billion in 2012.<ref name="First_Post">{{cite web|url=http://firstbiz.firstpost.com/biztech/2012-global-losses-from-phishing-estimated-at-1-5-bn-16850.html|title=2012 Global Losses From phishing Estimated At $1.5 Bn|publisher=FirstPost|date=20 February 2013|access-date=25 January 2019|url-status=live|archive-url=https://web.archive.org/web/20141221122958/http://firstbiz.firstpost.com/biztech/2012-global-losses-from-phishing-estimated-at-1-5-bn-16850.html|archive-date=21 December 2014}}</ref> Two of the well-known phishing methods are Covert Redirect and Open Redirect.

Proposed solutions vary. Large security companies like [[McAfee]] already design governance and compliance suites to meet post-9/11 regulations,<ref>{{Cite news|author=Prince, Brian|title=McAfee Governance, Risk and Compliance Business Unit|url=http://www.eweek.com/c/a/Security/McAfee-Governance-Risk-and-Compliance-Business-Unit/|work=eWEEK|publisher=Ziff Davis Enterprise Holdings|date=9 April 2008|access-date=25 April 2008|archive-date=21 April 2024|archive-url=https://web.archive.org/web/20240421053243/https://www.eweek.com/security/mcafee-governance-risk-and-compliance-business-unit/|url-status=live}}</ref> and some, like [[Finjan Holdings]] have recommended active real-time inspection of programming code and all content regardless of its source.<ref name="Ben-Itzhak">{{Cite news|author=Ben-Itzhak, Yuval|title=Infosecurity 2008 – New defence strategy in battle against e-crime|url=http://www.computerweekly.com/Articles/2008/04/18/230345/infosecurity-2008-new-defence-strategy-in-battle-against.htm|work=ComputerWeekly|publisher=Reed Business Information|date=18 April 2008|access-date=20 April 2008|url-status=live|archive-url=https://web.archive.org/web/20080604061926/http://www.computerweekly.com/Articles/2008/04/18/230345/infosecurity-2008-new-defence-strategy-in-battle-against.htm|archive-date=4 June 2008}}</ref> Some have argued that for enterprises to see Web security as a business opportunity rather than a [[cost centre (business)|cost centre]],<ref>{{Cite news|author=Preston, Rob|title=Down To Business: It's Past Time To Elevate The Infosec Conversation|url=http://www.informationweek.com/news/security/client/showArticle.jhtml?articleID=207100989|work=InformationWeek|publisher=United Business Media|date=12 April 2008|access-date=25 April 2008|url-status=live|archive-url=https://web.archive.org/web/20080414031843/http://www.informationweek.com/news/security/client/showArticle.jhtml?articleID=207100989|archive-date=14 April 2008}}</ref> while others call for "ubiquitous, always-on [[digital rights management]]" enforced in the infrastructure to replace the hundreds of companies that secure data and networks.<ref>{{Cite news|author=Claburn, Thomas|title=RSA's Coviello Predicts Security Consolidation|url=http://www.informationweek.com/news/security/showArticle.jhtml?articleID=197003826|work=InformationWeek|publisher=United Business Media|date=6 February 2007|access-date=25 April 2008|url-status=live|archive-url=https://web.archive.org/web/20090207091418/http://www.informationweek.com/news/security/showArticle.jhtml?articleID=197003826|archive-date=7 February 2009}}</ref> [[Jonathan Zittrain]] has said users sharing responsibility for computing safety is far preferable to locking down the Internet.<ref>{{Cite news|first=Carolyn|last=Duffy Marsan|title=How the iPhone is killing the 'Net|url=http://www.networkworld.com/news/2008/040908-zittrain.html|work=Network World|publisher=IDG|date=9 April 2008|access-date=17 April 2008|url-status=dead|archive-url=https://web.archive.org/web/20080414043829/http://www.networkworld.com/news/2008/040908-zittrain.html|archive-date=14 April 2008}}</ref>

== Privacy ==
{{Main|Internet privacy}}
Every time a client requests a web page, the server can identify the request's [[IP address]]. Web servers usually log IP addresses in a [[log file]]. Also, unless set not to do so, most web browsers record requested web pages in a viewable ''history'' feature, and usually [[Web cache|cache]] much of the content locally. Unless the server-browser communication uses HTTPS encryption, web requests and responses travel in plain text across the Internet and can be viewed, recorded, and cached by intermediate systems. Another way to hide [[personally identifiable information]] is by using a [[virtual private network]]. A VPN [[encryption|encrypts]] traffic between the client and VPN server, and masks the original IP address, lowering the chance of user identification.

When a web page asks for, and the user supplies, personally identifiable information—such as their real name, address, e-mail address, etc. web-based entities can associate current web traffic with that individual. If the website uses [[HTTP cookie]]s, username, and password authentication, or other tracking techniques, it can relate other web visits, before and after, to the identifiable information provided. In this way, a web-based organization can develop and build a profile of the individual people who use its site or sites. It may be able to build a record for an individual that includes information about their leisure activities, their shopping interests, their profession, and other aspects of their [[demographic profile]]. These profiles are of potential interest to marketers, advertisers, and others. Depending on the website's [[terms and conditions]] and the local laws that apply information from these profiles may be sold, shared, or passed to other organizations without the user being informed. For many ordinary people, this means little more than some unexpected emails in their inbox or some uncannily relevant advertising on a future web page. For others, it can mean that time spent indulging an unusual interest can result in a deluge of further targeted marketing that may be unwelcome. Law enforcement, counterterrorism, and espionage agencies can also identify, target, and track individuals based on their interests or proclivities on the Web.

[[Social networking]] sites usually try to get users to use their real names, interests, and locations, rather than pseudonyms, as their executives believe that this makes the social networking experience more engaging for users. On the other hand, uploaded photographs or unguarded statements can be identified to an individual, who may regret this exposure. Employers, schools, parents, and other relatives may be influenced by aspects of social networking profiles, such as text posts or digital photos, that the posting individual did not intend for these audiences. [[Cyberbullying|Online bullies]] may make use of personal information to harass or [[cyberstalking|stalk]] users. Modern social networking websites allow fine-grained control of the privacy settings for each posting, but these can be complex and not easy to find or use, especially for beginners.<ref>{{cite journal|last=boyd|first=danah|author2=Hargittai, Eszter|title=Facebook privacy settings: Who cares?|journal=First Monday|date=July 2010|volume=15|issue=8|doi=10.5210/fm.v15i8.3086 |doi-access=free }}</ref> Photographs and videos posted onto websites have caused particular problems, as they can add a person's face to an online profile. With modern and potential [[Facial recognition system|facial recognition technology]], it may then be possible to relate that face with other, previously anonymous, images, events, and scenarios that have been imaged elsewhere. Due to image caching, mirroring, and copying, it is difficult to remove an image from the World Wide Web.

== Standards ==
{{Main|Web standards}}
Web standards include many interdependent standards and specifications, some of which govern aspects of the [[Internet]], not just the World Wide Web. Even when not web-focused, such standards directly or indirectly affect the development and administration of websites and [[web service]]s. Considerations include the [[interoperability]], [[accessibility]] and [[usability]] of web pages and web sites.

Web standards, in the broader sense, consist of the following:
* ''Recommendations'' published by the [[World Wide Web Consortium]] (W3C)<ref>{{cite web | url=http://www.w3.org/TR/#Recommendations | title=W3C Technical Reports and Publications | publisher=W3C | access-date=19 January 2009 | archive-date=15 July 2018 | archive-url=https://web.archive.org/web/20180715045533/http://www.w3.org/TR/#Recommendations | url-status=live }}</ref>
* "Living Standard" made by the [[Web Hypertext Application Technology Working Group]] (WHATWG)
* ''[[Request for Comments]]'' (RFC) documents published by the [[Internet Engineering Task Force]] (IETF)<ref>{{cite web | url=http://www.ietf.org/rfc.html | title=IETF RFC page | publisher=IETF | access-date=19 January 2009 | archive-url=https://web.archive.org/web/20090202124230/http://www.ietf.org/rfc.html | archive-date=2 February 2009 | url-status=dead }}</ref>
* ''Standards'' published by the [[International Organization for Standardization]] (ISO)<ref>{{cite web | url=http://www.iso.org/iso/search.htm?qt=world+wide+web&published=on&active_tab=standards | title=Search for World Wide Web in ISO standards | publisher=ISO | access-date=19 January 2009 | archive-date=4 March 2016 | archive-url=https://web.archive.org/web/20160304072654/http://www.iso.org/iso/search.htm?qt=world+wide+web&published=on&active_tab=standards | url-status=live }}</ref>
* ''Standards'' published by [[Ecma International]] (formerly ECMA)<ref>{{cite web | url=http://www.ecma-international.org/publications/index.html | title=Ecma formal publications | publisher=Ecma | access-date=19 January 2009 | archive-date=27 December 2017 | archive-url=https://web.archive.org/web/20171227133707/http://www.ecma-international.org/publications/index.html | url-status=live }}</ref>
* ''The [[Unicode]] Standard'' and various ''Unicode Technical Reports'' (UTRs) published by the [[Unicode Consortium]]<ref>{{cite web | url=https://www.unicode.org/reports/index.html | title=Unicode Technical Reports | publisher=Unicode Consortium | access-date=19 January 2009 | archive-date=2 January 2022 | archive-url=https://web.archive.org/web/20220102053035/https://www.unicode.org/reports/index.html | url-status=live }}</ref>
* Name and number registries maintained by the [[Internet Assigned Numbers Authority]] (IANA)<ref>{{cite web | url=https://www.iana.org/ | title=IANA home page | publisher=IANA | access-date=19 January 2009 | archive-date=24 February 2011 | archive-url=https://web.archive.org/web/20110224160727/http://www.iana.org/ | url-status=live }}</ref>

Web standards are not fixed sets of rules but are constantly evolving sets of finalized technical specifications of web technologies.<ref>{{cite book | first= Leslie | last= Sikos | title= Web standards – Mastering HTML5, CSS3, and XML | publisher= [[Apress]] | year= 2011 | isbn= 978-1-4302-4041-9 | url= http://www.masteringhtml5css3.com/ | access-date= 12 March 2019 | archive-date= 2 April 2015 | archive-url= https://web.archive.org/web/20150402152305/http://www.masteringhtml5css3.com/ | url-status= dead }}</ref> Web standards are developed by [[standards organization]]s—groups of interested and often competing parties chartered with the task of standardization—not technologies developed and declared to be a standard by a single individual or company. It is crucial to distinguish those specifications that are under development from the ones that already reached the final development status (in the case of [[W3C]] specifications, the highest maturity level).

== Accessibility ==
{{Main|Web accessibility}}
There are methods for accessing the Web in alternative mediums and formats to facilitate use by individuals with [[disability|disabilities]]. These disabilities may be visual, auditory, physical, speech-related, cognitive, neurological, or some combination. Accessibility features also help people with temporary disabilities, like a broken arm, or ageing users as their abilities change.<ref name=WAI>{{cite web|title=Web Accessibility Initiative (WAI)|url=http://www.w3.org/WAI|publisher=World Wide Web Consortium|access-date=7 April 2009|url-status=dead|archive-url=https://web.archive.org/web/20090402001730/http://www.w3.org/WAI/|archive-date=2 April 2009}}</ref> The Web is receiving information as well as providing information and interacting with society. The World Wide Web Consortium claims that it is essential that the Web be accessible, so it can provide equal access and [[equal opportunity]] to people with disabilities.<ref>{{cite web|title=Developing a Web Accessibility Business Case for Your Organization: Overview|url=http://www.w3.org/WAI/bcase/Overview|publisher=World Wide Web Consortium|access-date=7 April 2009|url-status=live|archive-url=https://web.archive.org/web/20090414173026/http://www.w3.org/WAI/bcase/Overview|archive-date=14 April 2009}}</ref> Tim Berners-Lee once noted, "The power of the Web is in its universality. Access by everyone regardless of disability is an essential aspect."<ref name=WAI /> Many countries regulate web accessibility as a requirement for websites.<ref>{{cite web|title=Legal and Policy Factors in Developing a Web Accessibility Business Case for Your Organization|url=http://www.w3.org/WAI/bcase/pol|publisher=World Wide Web Consortium|access-date=7 April 2009|url-status=live|archive-url=https://web.archive.org/web/20090405142512/http://www.w3.org/WAI/bcase/pol|archive-date=5 April 2009}}</ref> International co-operation in the W3C [[Web Accessibility Initiative]] led to simple guidelines that web content authors as well as software developers can use to make the Web accessible to persons who may or may not be using [[assistive technology]].<ref name=WAI /><ref>{{cite web|title=Web Content Accessibility Guidelines (WCAG) Overview|url=http://www.w3.org/WAI/intro/wcag.php|publisher=World Wide Web Consortium|access-date=7 April 2009|url-status=live|archive-url=https://web.archive.org/web/20090401074742/http://www.w3.org/WAI/intro/wcag.php|archive-date=1 April 2009}}</ref>

== Internationalisation ==
[[File:World Map of Web Index 2014.svg|thumb|upright=1.05|A global map of the [[Web Index]] for countries in 2014]]
The W3C [[Internationalization and localization|Internationalisation]] Activity assures that web technology works in all languages, scripts, and cultures.<ref>{{cite web|title=Internationalization (I18n) Activity|url=http://www.w3.org/International/|publisher=World Wide Web Consortium|access-date=10 April 2009|url-status=live|archive-url=https://web.archive.org/web/20090416052903/http://www.w3.org/International/|archive-date=16 April 2009}}</ref> Beginning in 2004 or 2005, [[Unicode]] gained ground and eventually in December 2007 surpassed both [[ASCII]] and Western European as the Web's most frequently used [[Character encoding#Code pages|character map]].<ref>{{Cite news|author=Davis, Mark|title=Moving to Unicode 5.1|url=http://googleblog.blogspot.com/2008/05/moving-to-unicode-51.html|date=5 April 2008|access-date=10 April 2009|url-status=live|archive-url=https://web.archive.org/web/20090521191341/http://googleblog.blogspot.com/2008/05/moving-to-unicode-51.html|archive-date=21 May 2009}}</ref> Originally {{IETF RFC|3986}} allowed resources to be identified by [[URI]] in a subset of US-ASCII. {{IETF RFC|3987}} allows more characters—any character in the [[Universal Character Set]]—and now a resource can be identified by [[Internationalized Resource Identifier|IRI]] in any language.<ref>{{cite press release|title=World Wide Web Consortium Supports the IETF URI Standard and IRI Proposed Standard|url=http://www.w3.org/2004/11/uri-iri-pressrelease.html|date=26 January 2005|publisher=World Wide Web Consortium|access-date=10 April 2009|url-status=live|archive-url=https://web.archive.org/web/20090207070535/http://www.w3.org/2004/11/uri-iri-pressrelease.html|archive-date=7 February 2009}}</ref>
<!--== Statistics ==
{{update section}}
Between 2005 and 2010, the number of Web users doubled, and was expected to surpass two billion in 2010.<ref>{{cite news|url=https://www.reuters.com/article/2010/10/19/us-telecoms-internet-idUSTRE69I24720101019|title=Internet users to exceed 2&nbsp;billion ...|work=Reuters|date=19 October 2010|access-date=9 February 2011|first=Jonathan|last=Lynn|url-status=live|archive-url=https://web.archive.org/web/20110224041600/http://www.reuters.com/article/2010/10/19/us-telecoms-internet-idUSTRE69I24720101019|archive-date=24 February 2011}}</ref> Early studies in 1998 and 1999 estimating the size of the Web using capture/recapture methods showed that much of the Web was not indexed by search engines and the Web was much larger than expected.<ref>{{cite journal|last1=Lawrence|first1=S.|last2=Giles|first2=C.L.|year=1998|title=Searching the World Wide Web|url=http://circ.ahajournals.org/content/106/12/1556.full.pdf|journal=Science|volume=280|issue=5360|pages=98–100|doi=10.1126/science.280.5360.98|pmid=9525866|bibcode=1998Sci...280...98L|citeseerx=10.1.1.33.3985}}</ref><ref>{{cite journal|last1=Lawrence|first1=S.|last2=Giles|first2=C.L.|year=1999|title=Accessibility of Information on the Web|journal=Nature|volume=400|issue=6740|pages=107–109|doi=10.1038/21987|pmid=10428673|bibcode=1999Natur.400..107L}}</ref> According to a 2001 study, there was a massive number, over 550&nbsp;billion, of documents on the Web, mostly in the invisible Web, or [[Deep Web (search indexing)|Deep Web]].<ref>{{cite web|url=http://www.brightplanet.com/resources/details/deepweb.html|archive-url=https://web.archive.org/web/20080404044203/http://www.brightplanet.com/resources/details/deepweb.html|archive-date=4 April 2008|title=The 'Deep' Web: Surfacing Hidden Value|publisher=Brightplanet.com|access-date=27 July 2009}}</ref> A 2002 survey of 2,024 million web pages<ref>{{cite web|url=http://www.netz-tipp.de/languages.html|title=Distribution of languages on the Internet|publisher=Netz-tipp.de|access-date=27 July 2009|url-status=live|archive-url=https://web.archive.org/web/20130827044617/http://www.netz-tipp.de/languages.html|archive-date=27 August 2013}}</ref> determined that by far the most web content was in the English language: 56.4%; next were pages in German (7.7%), French (5.6%), and Japanese (4.9%). A more recent study, which used web searches in 75 different languages to sample the Web, determined that there were over 11.5 billion web pages in the [[Surface Web|publicly indexable web]] as of the end of January 2005.<ref>{{cite web|first=Alessio|last=Signorini|url=http://wifiscan.fr/research/The_Indexable_Web_is_More_than_11_Billion_Pages.pdf|title=The Indexable Web is More than 11.5 Billion Pages|publisher=citeseerx.ist.psu.edu|access-date=4 February 2015|url-status=dead|archive-url=https://web.archive.org/web/20150204182728/http://wifiscan.fr/research/The_Indexable_Web_is_More_than_11_Billion_Pages.pdf|archive-date=4 February 2015}}</ref> {{As of|2009|3}}, the indexable web contains at least 25.21&nbsp;billion pages.<ref>{{cite web|url=http://www.worldwidewebsize.com/|title=The size of the World Wide Web|publisher=Worldwidewebsize.com|access-date=27 July 2009|url-status=live|archive-url=https://web.archive.org/web/20130430051601/http://worldwidewebsize.com/|archive-date=30 April 2013}}</ref> On 25 July 2008, Google software engineers Jesse Alpert and Nissan Hajaj announced that [[Google Search]] had discovered one trillion unique URLs.<ref>{{cite web|url=http://googleblog.blogspot.com/2008/07/we-knew-web-was-big.html|title=We knew the web was big...|last=Alpert|first=Jesse|author2=Hajaj, Nissan|date=25 July 2008|work=The Official Google Blog|url-status=live|archive-url=https://web.archive.org/web/20130520100904/http://googleblog.blogspot.com/2008/07/we-knew-web-was-big.html|archive-date=20 May 2013}}</ref> {{As of|2009|5}}, over 109.5&nbsp;million domains operated.<ref name=NI>{{cite web|title=Domain Counts & Internet Statistics|url=http://www.domaintools.com/internet-statistics/|publisher=Name Intelligence|access-date=17 May 2009}}</ref> {{failed verification|date=November 2011}} Of these, 74% were commercial or other domains operating in the [[generic top-level domain]] ''com''.<ref name=NI /> Statistics measuring a website's popularity, such as the [[Alexa Internet]] rankings, are usually based either on the number of [[page view]]s or on associated server "[[hit (internet)|hits]]" (file requests) that it receives.-->

== See also ==
{{portal|Engineering|Internet|World}}
{{div col|colwidth=22em}}
* [[Decentralized web]]
* [[Electronic publishing]]
* [[Gopher (protocol)]], an early alternative to the WWW
* [[Internet metaphors]]
* [[Internet security]]
* [[Lists of websites]]
* [[Minitel]], a predecessor of the WWW
* [[Streaming media]]
* [[Web 1.0]]
* [[Web 2.0]]
* [[Semantic Web|Web 3.0]]
* [[Web3]]
* [[Web3D]]
* [[Web development tools]]
* [[Web literacy]]
*[[darknet]]
{{div col end}}

== References ==
{{Reflist|refs=
<ref name="wright2009">{{cite news
 | last = Wright
 | first = Alex
 | title = Exploring a 'Deep Web' That Google Can't Grasp
 | work = The New York Times
 | date = 22 February 2009
 | url = https://www.nytimes.com/2009/02/23/technology/internet/23search.html?th&emc=th
 | access-date = 23 February 2009
 | archive-date = 1 March 2020
 | archive-url = https://web.archive.org/web/20200301174914/https://www.nytimes.com/2009/02/23/technology/internet/23search.html?th&emc=th
 | url-status = live
 }}</ref>
}}

== Further reading ==
* {{Cite journal|author1=Berners-Lee, Tim|author2=Bray, Tim|author3=Connolly, Dan|author4=Cotton, Paul|author5=Fielding, Roy|author6=Jeckle, Mario|author7=Lilley, Chris|author8=Mendelsohn, Noah|author9=Orchard, David |author10=Walsh, Norman|author11=Williams, Stuart|title=Architecture of the World Wide Web, Volume One|date=15 December 2004|version=Version 20041215|url=http://www.w3.org/TR/webarch/ |website=W3C}}
* {{cite journal|title=The World Wide Web: Past, Present and Future|url=http://www.w3.org/People/Berners-Lee/1996/ppf.html|date=August 1996|last=Berners-Lee|first=Tim |website=W3C}}
* Brügger, Niels, ed, ''Web25: Histories from the first 25 years of the World Wide Web'' (Peter Lang, 2017).
* {{Cite news |author1=Fielding, R.|author2=Gettys, J.|author3=Mogul, J.|author4=Frystyk, H.|author5=Masinter, L.|author6=Leach, P.|author7=Berners-Lee, T.|title=Hypertext Transfer Protocol&nbsp;– HTTP/1.1|publisher=Information Sciences Institute|date=June 1999|version=Request For Comments 2616}}
* Niels Brügger, ed. ''Web History'' (2010) 362 pages; Historical perspective on the World Wide Web, including issues of culture, content, and preservation.
* {{cite web|author=Polo, Luciano|title=World Wide Web Technology Architecture: A Conceptual Analysis|year=2003|work=New Devices|url=http://www.newdevices.com/publicaciones/www/index.html}}
* Skau, H.O. (March 1990). "The World Wide Web and Health Information". ''New Devices''.

== External links ==
{{Commons category|World Wide Web}}
{{Wikibooks|Nets, Webs and the Information Infrastructure}}
* [https://info.cern.ch/hypertext/WWW/TheProject.html The first website]
* [https://www.w3.org/History/19921103-hypertext/hypertext/WWW/ Early archive of the first Web site]
* [https://www.mit.edu/people/mkgray/net/ Internet Statistics: Growth and Usage of the Web and the Internet]
* [https://www.livinginternet.com/w/w.htm Living Internet] A comprehensive history of the Internet, including the World Wide Web
* [https://www.w3.org/ World Wide Web Consortium (W3C)]
* [https://www.w3.org/Protocols/NL-PerfNote.html W3C Recommendations Reduce "World Wide Wait"]
* [https://www.worldwidewebsize.com/ World Wide Web Size] Daily estimated size of the World Wide Web
* [https://web.archive.org/web/20110501162838/http://cle.ens-lyon.fr/40528325/0/fiche___pagelibre/ Antonio A. Casilli, Some Elements for a Sociology of Online Interactions]
* [https://www.web-graph.org/ The Erdős Webgraph Server] {{Webarchive|url=https://web.archive.org/web/20210301013100/http://web-graph.org/ |date=1 March 2021 }} offers weekly updated graph representation of a constantly increasing fraction of the WWW
* [https://www.techchange.org/work/u-s-global-development-lab-25th-anniversary-of-the-world-wide-web/ The 25th Anniversary of the World Wide Web] {{Webarchive|url=https://web.archive.org/web/20210711202508/https://www.techchange.org/work/u-s-global-development-lab-25th-anniversary-of-the-world-wide-web/ |date=11 July 2021 }} is an animated video produced by [[USAID]] and [[TechChange]] which explores the role of the WWW in addressing extreme [[poverty]]

{{Telecommunications}}
{{Web syndication}}
{{Semantic Web}}
{{Authority control}}

[[Category:20th-century inventions]]
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[[Category:Computer-related introductions in 1989]]
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[[Category:Search engine software]]
[[Category:Tim Berners-Lee]]
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[[Category:World Wide Web| ]]