A Wiki is a webpage that can be edited by the users. Usually, the software that supports this editing has workflow, approval, undo, and redo capability.
You can see a table of different Wiki software, some free, some not at one of the most famous Wikis, Wikipedia. Many of these Wiki software packages are free.
What might you use a wiki for?
- Internal communication
- Project Management
- Client communication
- Training manuals
- Technical manuals
- Program development
I'm sure I missed a bunch, but this will give you an idea.
