This document defines wikis and discusses their history and uses. It provides three key points: 1) A wiki is a type of website that allows users to collaboratively modify and edit its content and structure directly from a web browser. 2) Wikis were invented in 1994 by Ward Cunningham and the first wiki was launched in 1995. The name "wiki" comes from the Hawaiian word for "quick." 3) Wikis are useful collaboration tools that allow groups to jointly develop and refine ideas, but information on wikis may not always be reliable unless it is thoroughly sourced and verified.