An Internet forum is a facility on the World Wide Web for holding discussions, or the web application software used to provide the facility. Web-based forums, which date from around 1995, perform a similar function as the dial-up bulletin boards and Internet newsgroups that were numerous in the 1980s and 1990s. A sense of virtual community often develops around forums that have regular users. Technology, computer games, and politics are popular areas for forum themes, but there are forums for a huge number of different topics. Internet forums are prevalent in most developed countries. The largest forum in the world is 2channel, a Japanese site. The English-speaking world is dominated less by one large forum and more by many smaller forums, including SomethingAwful, Gaia Online, GameFAQs and IGN.
Small forums are often based around a single subject. Usually there is an "off-topic" forum where users can post any items they find interesting or play "forum games". Larger Internet forums are in general more subject to public conflicts between users, catch phrases, and private jokes. Depending on the level of moderation there may also be conflicts between users and administrators.

Like other forms of online communication, Internet forums are home to many heated exchanges and rivalries. Often, administrators and moderators ask users to conform to netiquette; if they leave a forum unmoderated it may degenerate and become useless for discussion. However, some forums allow only selective postings effectively censoring information even though the posts might have followed netiquette and were in good spirit. This is especially true of team/country specific forums that do not wish to see a different viewpoint of the same topic/post.