A wiki is a webpage that people can build and use together. The most well-known wiki is probably wikipedia--which allows users across the world to enter information about anything, thus producing one of the largest encyclopedias possible. Of course, wikipedia is not necessarily the most reliable information source, you have to check it against other sources, but it is incredibly useful to have so much information at your fingertips. No normal publisher could produce so much unless they could somehow hire all the writers of the world, and even then...

So a wiki is strongest when it has a number of people entering information, links, movies, and other data that can inform on a particular topic or set of topics. It is DEMOCRATIC, in that generally all participants can make changes freely, including adding pages, editing pages, adding links, deleting information, and so forth. It can be LESS ORGANIZED given that everyone is participating and individuals may have different visions as to how the information should be presented, organized, shared, etc.

Competing and comparing visions requires freedom and the willingness to DIVE IN, but also requires more communication and greater care and respect for the opinions and ideas of others. A Wiki is a virtual community of ideas.