Anonymous users are users of a site that do not have an existing account on that site.

Anonymous users are visitors to a site that does not own an existing account on that site. Such users are regarded as anonymous. For websites that allow anonymous users to contribute to the site, such users may be identified by their IP address, or given an option to choose a nickname before posting comments.

Anonymous users are basically just normal visitors to the site and often does not have the same amount of privileges as a normal user.