{{Infobox
| title = Wiki
| image = https://commons.wikimedia.org/wiki/Special:FilePath/Ward%20Cunningham%20-%20Commons-1.jpg?width=320
| caption = Editing a page directly in the browser
| label1 = First example
| data1 = WikiWikiWeb, 25 March 1995
| label2 = Created by
| data2 = Ward Cunningham
| label3 = Named after
| data3 = Hawaiian ''wiki wiki'', "quick"
| label4 = Defining feature
| data4 = Any reader can edit any page
}}

A '''wiki''' is a website whose pages can be created and edited by its readers, directly in the browser, using a simplified markup language. The defining choice is that editing is open by default and review happens after publication rather than before.

== Origin ==

[[Ward Cunningham]] built the first wiki, WikiWikiWeb, and opened it on 25 March 1995 as a place for programmers to record design patterns. He named it after the ''Wiki Wiki'' shuttle buses at Honolulu airport; ''wiki wiki'' is Hawaiian for "quick". Speed was the point: Cunningham wanted the gap between noticing that a page was wrong and fixing it to be as close to zero as possible.<ref>Leuf, Bo and Cunningham, Ward. ''The Wiki Way: Quick Collaboration on the Web''. Addison-Wesley, 2001.</ref>

== How a wiki works ==

Four mechanisms, taken together, make open editing survivable:

; Edit anywhere : Every page has an edit view containing its source. There is no separate authoring tool and no publishing step.
; Simplified markup : [[Help:Editing|Wikitext]] keeps the source readable, so a page can be edited by someone who does not write HTML.
; Complete revision history : Every save is stored as a new revision. Nothing is overwritten, so any change can be inspected, compared and undone.
; Links to pages that do not exist : Writing a link to a missing page creates a request for it. Following the link opens an empty editor. Articles grow outward from red links.

Because any change can be reversed from the history, a bad edit costs little to correct. Wikis rely on this to keep editing open by default.

== Structure ==

Wikis are organised by linking rather than by hierarchy. There is no fixed tree of folders; a page belongs wherever other pages point at it. Two conventions supplement this: '''categories''', which tag pages by subject and generate an index, and '''namespaces''', which separate content from the discussion and administration around it. On this site, ''[[Help:Editing|Help:]]'' pages hold instructions, ''[[Template:Infobox|Template:]]'' pages hold reusable fragments and ''[[Special:AllPages|Special:]]'' pages are generated by the software. Discussion is deliberately not a namespace here: it is [[Help:Discussions|a separate system]] of posted messages rather than pages that everyone edits.

== Uses ==

Public encyclopedias are the most visible application, but the pattern is general. Wikis are used for software documentation, internal company knowledge bases, project planning and note-taking. The trade-off is consistent everywhere: a wiki lowers the cost of contribution and raises the cost of maintaining consistency, which suits work where getting information written down at all is the hard part.

== See also ==

* [[Encyclopedia]]
* [[Hypertext]]
* [[World Wide Web]]
* [[Help:Editing]]

== References ==

<references />

[[Category:Computing]]
[[Category:World Wide Web]]