Wikipedia is a free encyclopedia that anyone can edit, and is one of the most popular innovations of Web 2.0. Its content is free and written collaboratively by anyone who has access to the internet. Created in 2001, Wikipedia has since become the internet’s largest and most popular reference site. It is actively updated in over a hundred languages, and the English Wikipedia contains over one million articles.

One of the main criticisms Wikipedia receives is its inconsistency and the unauthoritative way submissions are received. Anyone can edit the articles, even under an anonymous name. To ensure quality and accurate content, edits and submissions are monitored by staff and volunteers, but it’s still prone to inaccurate information. Citing Wikipedia as a reference is usually discouraged.