WhatIsaWiki

A wiki is a collection of interlinked web pages, each of which can be visited and edited by anyone.  You can even edit ''this'' page: just click "Edit text of this page" below.  

So it's a collaborative website, constantly expanding as new people add pages about their interests, comment on old pages, etc.

The original wiki http://c2.com/cgi/wiki might give you an idea of ''one'' way a fully-developed wiki might look.

''Question about the safety of wikis removed to the WikiPediaFaq.''