Internet forums are also commonly referred to as web forums, message boards, discussion boards, (electronic) discussion groups, discussion forums, bulletin boards, fora (the Latin plural) or simply forums. Both fora and forums are considered correct, though fora is typically preferred. The term "forum" and "board" may refer to the entire community, or a specific sub-forum dealing with a distinct topic. Such forums perform a similar function as the dial-up bulletin board systems and Internet newsgroups that were numerous in the 1980s and 1990s. Early web-based forums such as UBB.classic date back as far as 1996. A sense of virtual community often develops around forums that have regular users. Technology, computer games and/or video games, fashion, religion, and politics are popular areas for forum themes, but there are forums for a huge number of different topics Internet slang and image macros popular across the internet are abundant and most widely used in internet forums.

A Bulletin Board System or BBS is a computer system running software that allows users to dial into the system over a phone line and, using a terminal program, perform functions such as downloading software and data, uploading data, reading news, and exchanging messages with other users.

During their heyday (from the early 1980s to the mid 1990s), many BBSes were run as a hobby free of charge by the "SysOp" (system operator), while other BBSes charged their users a subscription fee for access, or were operated by a business as a means supporting their customers. Still others were run by Internet service providers as part of their service to subscribers.

In some parts of Asia and Europe the term BBS may be used to refer to any online forum or message board.

Bulletin board systems were in many ways a precursor to the modern form of the World Wide Web and other aspects of the Internet. BBSes were a highly social phenomenon and were used for meeting people and having discussions in message boards as well as for publishing articles, downloading software, playing games and many more things using a single application.

The BBS was also a local phenomenon, as one had to dial into a BBS with a phone line and would have to pay additional long distance charges for a BBS out of the local area, as opposed to less expensive local charges. Thus, many users of a given BBS usually lived in the same area, and it was common for activities such as BBS Meets or Get Togethers (GTs or GTGs), where everyone from the board would gather and meet face to face, to take place.