wiki is a website that can be edited by anyone who has been granted editing rights. The collaborative encyclopedia //Wikipedia// is one of the best-known wikis. (Wikipedia).
Wikis are easy to use because they are WYSIWYG--what you see is what you get. So users do not need to know any coding languages. In fact, I often say that if you can use Microsoft Word then you can create a wiki.
Wiki Features:
  • easy to create & update
  • create multiple pages with the click of a button
  • follow the history of any changes made & who made them
  • group discussions
  • embed photos, documents, audio, & video
  • embed widgets (little program apps) including interactive maps, calendars, videos, slide shows, polls, etc.
  • statistics easily accessible

Lee LeFever
http://www.commoncraft.com/video/wikis
Some recommended sites for creating wikis:
www.wikispaces.com
www.pbwiki.com
http://wikisineducation.wetpaint.com/