Wikis

A Wiki is an online collaborative tool. It can be used in an informal way because it is so easy to add information. It can be edited within a browser. So that means anyone can add to a wiki. Although this is probably also the weakness of the wiki because the information may not always be reliable.

Wikis can be used to share information, organise events like conferences or even a trip, and more. I discovered this explanation of the Wiki, Wikis in Plain English,  by Commoncraft, which I think just about says it all.