Editing Hyperlink (section)

==Uses in various technologies==

===HTML===
{{Main article|HTML element#Anchor}}
[[Tim Berners-Lee]] saw the possibility of using hyperlinks to link any information to any other information over the [[Internet]]. Hyperlinks were therefore integral to the creation of the [[World Wide Web]]. Web pages are written in the hypertext mark-up language [[HTML]].

This is what a hyperlink to the home page of the [[W3C organization]] could look like in HTML code:

<syntaxhighlight lang="html">
<a href="https://www.w3.org/">W3C organization website</a>
</syntaxhighlight>

This HTML code consists of several [[HTML element|tags]]:
* The hyperlink starts with an anchor opening tag '''<nowiki><a</nowiki>''', and includes a hyperlink reference '''<nowiki>href="https://www.w3.org/</nowiki>"''' to the '''[[URL]]''' for the page. (The URL is enclosed in quotes.)
* The [[URL]] is followed by '''>''', marking the end of the anchor opening tag.
* The words that follow identify what is being linked; this is the only part of the code that is ordinarily visible on the screen when the page is rendered, but when the cursor hovers over the link, many browsers display the target URL somewhere on the screen, such as in the lower left-hand corner.
* Typically these words are underlined and colored (for example, blue for a link that has not yet been visited and purple for a link already visited).
* The anchor closing tag ('''<nowiki></a></nowiki>''') terminates the hyperlink code.
* The '''<nowiki><a></nowiki>''' tag can also consist of various [[HTML attribute|attributes]] such as the "rel" attribute which specifies the relationship between the current document and linked document.

[[Webgraph]] is a [[Graph (discrete mathematics)|graph]], formed from [[web page]]s as vertices and hyperlinks, as directed edges.

===XLink===

The [[W3C]] recommendation called [[XLink]] describes hyperlinks that offer a far greater degree of functionality than those offered in HTML. These '''extended links''' can be ''multidirectional'', remove linking from, within, and between XML documents. It can also describe ''simple links'', which are unidirectional and therefore offer no more functionality than hyperlinks in HTML.{{Citation needed |date=May 2024}}

===Permalinks===
{{Main article|Digital preservation}}
[[Permalink]]s are URLs that are intended to remain unchanged for many years into the future, yielding hyperlinks that are less susceptible to [[link rot]]. Permalinks are often rendered simply, that is, as friendly URLs, so as to be easy for people to type and remember. Permalinks are used in order to [[Pointer (computer programming)#Typed pointers and casting|point]] and [[URL redirection#Meaningful, persistent aliases for long or changing URLs|redirect]] readers to the same [[Web page]], blog post or any online digital media.<ref name="techopedia.com">{{cite web | url = https://www.techopedia.com/definition/4900/permanent-link-permalink | title = Definition of Permanent Link (Permalink) | website = techopedia.com| access-date = Oct 31, 2018 | archive-date = November 1, 2018 | archive-url = https://web.archive.org/web/20181101015428/https://www.techopedia.com/definition/4900/permanent-link-permalink | url-status = live }}</ref>

The scientific literature is a place where link persistence is crucial to the public knowledge. A 2013 study in [[BMC Bioinformatics]] analyzed 15,000 links in abstracts from Thomson Reuters' [[Web of Science]] citation index, founding that the median lifespan of Web pages was 9.3 years, and just 62% were archived.<ref>{{cite web | first = Leighton | last = W. Kille | url = https://journalistsresource.org/studies/society/internet/website-linking-best-practices-media-online-publishers | title = The growing problem of Internet 'link rot' and best practices for media and online publishers | website = journalistsresource.org| access-date = Oct 30, 2018 | archive-url = https://web.archive.org/web/20140919162322/https://journalistsresource.org/studies/society/internet/website-linking-best-practices-media-online-publishers | archive-date = September 19, 2014 | url-status = live| date = 2015-10-09 }}</ref> The median lifespan of a Web page constitutes high-degree variable, but its [[order of magnitude]] usually is of some months.<ref>{{cite web | url = https://blogs.loc.gov/thesignal/2011/11/the-average-lifespan-of-a-webpage/ | title = The Average Lifespan of a Webpage |date = November 8, 2011 |access-date = Oct 31, 2018 | archive-url = https://web.archive.org/web/20160908223104/https://blogs.loc.gov/thesignal/2011/11/the-average-lifespan-of-a-webpage/ | archive-date = September 8, 2016 | url-status = live}}</ref>