A discussion group is an online forum for individuals to discuss various topics amongst each other. People add their comments by posting a block of text to the group. Others can then comment and respond. In the early days of the Internet, USENET was the most popular type of discussion group, but now discussions mostly take place over the World Wide Web using special server software. The term discussion group encompasses bulletin boards, listservs, mailing lists, and newsgroups. An Internet forum, also known as a message board or discussion board, is a web application that provides for online discussions, and is the modern descendant of the bulletin board systems and existing Usenet news systems that were widespread in the 1980s and 1990s. ... Usenet is a distributed Internet discussion system that evolved from a general purpose UUCP network of the same name. ... Graphic representation of the world wide web around Wikipedia The World Wide Web (WWW, or simply Web) is an information space in which the items of interest, referred to as resources, are identified by global identifiers called Uniform Resource Identifiers (URI). ... Well-used bulletin board on the Infinite Corridor at MIT, November 2004. ... Listserv is an electronic mailing list software application, originally developed in the mid 1980s for the Bitnet computer network. ... A mailing list is a collection of names and addresses used by an individual or an organization to send material to multiple recipients. ... A newsgroup is a repository, usually within the Usenet system, for messages posted from many users at different locations. ...

Discussion groups differ from chatrooms and instant messaging because they usually deal with one topic and personal exchanges are typically discouraged. Discussion groups are often archived. These archives may be organized by thread, which means all the messages that reply to a starting message can be read in some order. Participants in discussion groups should realize that what they have to say will be public knowledge for years to come. For example, Google's Groups (formerly DejaNews) is an archive of Usenet articles dating back to 1981. Discussion group archives are sometimes the best way to find an answer to very obscure questions, such as how to fix a particular computer problem. A chat room is an online forum where people can chat online (talk by broadcasting messages to people on the same forum in real time). ... An instant messenger is a computer application which allows instant text communication between two or more people through a network such as the Internet. ... An archive is a collection of records, charters and other documents belonging to any state, community or family, and the building(s) its kept in. ... A thread is a large number of very thin fibers spun together, used in the manufacture of textiles and in sewing. ... Google, Inc. ... The Deja News logo as it appeared in 1997. ... 1981 is a common year starting on Thursday. ...