According to Wikipedia, the world largest Wiki site:
A Wiki <wee-kee> or <wick-ey> is a type of website that allows users to add, remove, or otherwise edit and change most content very quickly and easily.
Why is a Wiki site different from a usual hosted site?
When using this Wiki system you do not have to worry about technical details (like HTML language, editing pages, uploading files or creating a forum). On every page (where you have permissions) you will find an edit button - click it and you can edit content of the page! We provide an easy to learn syntax that the software converts into valid XHTML pages. Simply edit content, click save and your changes are published within seconds.
And that's all there is too it!
This site is a customizable piece of the Internet where Users can edit content, upload files, communicate and collaborate with others all over the World.
If you have any questions, contact: Rick Perez — Wiki Administrator.