The basic concept behind a wiki is to allow multiple people to contribute and update content in a central location, rather than pass copies of documents back and forth. A wiki also provides a common interface for creating and editing the content, without the need for other applications, just a web browser. Another concept is that of a revision history, allowing readers and editors to view changes to a document over time.

The most famous wiki is Wikipedia, but there are many other examples of how wikis can be used.