Wikis are websites that allow collaborative editing of their content. They enable multiple users to directly add, modify, or delete content via a web browser. Wikis are often used to create collaborative websites and power online communities. Some key benefits of wikis include their ability to facilitate instant collaboration, provide an accessible cumulative record of work, and give everyone an opportunity to contribute. However, wikis also have some potential downsides like requiring monitoring to prevent vandalism and lack of backup functions. Overall, wikis can be a useful tool for activities like compiling notes, homework assignments, reading groups, and collaborative writing when structured and monitored appropriately.