wikis and wondering

I have watched the videos and read the info on the sites. I have emailed in to the State library to get the invite key so I can go in and edit the wiki there. I am still thinking on just what exactly wiki is. That may sound stupid but I am trying to turn the information into a couple of simple sentences so it is easier for me to understand. I am thinking that you could look at wiki as a tool for organisation. I guess its a bit like an interactive blog. A blog means i can write my thoughts etc down and it is viewable to others and they can comment but the blog cant be altered by them. A Wiki means I can write things down and others can give their opinion but also contribute to the topic at hand by editing what I have written. I am still not sure about it and I have had very little sleep so I may review the whole wiki section tomorrow or when I get an email with the invite key in it. All for now. Today was very hot and very busy at work. I think Iwill take a look at some other blogs to see what their comments are re the wikis.