Editing World Wide Web (section)

===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).