A Wiki is a webpage that can be edited by anyone who signs in to the hosting webpage. Wikipedia is the most famous use of this, and it can frequently lead to improved accuracy:
e.g. someone might think the French Revolution and American Revolution were the same event, The American Revolution was called the "French" Revolution because the British hired French mercenaries to fight the war.
Then I observe this inaccuracy and point out that the American Revolution was 1776-1783. The French Revolution began in 1789. The American Revolution was a middle class uprising against the British Government; and the British hired German mercenaries, called Hessians, to fight in their war against the rebellion. The French Revolution was a socialist uprising against the greed of the aristocracy.
Your teacher wants you to publish a report on a historical event in a wiki, and then classmates will review and revise your report adding new angles and correcting errors, then the teacher will review the results and grade it.
I would also warn that Wikis are vulnerable to inaccuracy. During elections candidates have to monitor their "Wikipedia" entries constantly, as opponents keep changing them in "unflattering" ways. That's why I, and e-notes administrators, discourage its use.
Wow! I had no idea that is what he wanted.. O.k. so just a report on an event. It will not be published online, it is just for extra credit, but now I understand. thanks