What is a Wiki?

A Wiki is essentially a web publishing system. Wiki applications vary greatly, but most have a few common features.

Wikipedia describes a Wiki's key characteristics as:
"A wiki enables documents to be written collectively in a very simple markup language using a web browser. A single page in a wiki is referred to as a "wiki page", while the entire body of pages, which are usually highly interconnected via hyperlinks, is "the wiki"; in effect, a very simple, easier-to-use database.

A defining characteristic of wiki technology is the ease with which pages can be created and updated. Generally, there is no review before modifications are accepted. Most wikis are open to the general public without the need to register any user account. Sometimes session log-in is requested to acquire a "wiki-signature" cookie for autosigning edits. More private wiki servers require user authentication. However, many edits can be made in real-time, and appear almost instantaneously online..."