Forum
An Internet forum is an online discussion group. Its behavior is similar to the behavior of a traditional bulletin board. In a forum Internet users with common interests can post messages on various subjects. Forums are usually managed by a few individuals (usually called administrators) who are responsible for the content of the forum, technical maintenance of the website, rules and regulations etc.
In most forums an Internet user needs to register in order to post messages.
Usually when registering the user needs to accept a "terms of service"
agreement, which describes the policies of the forum.
Forums may sometimes be called
newsgroups.
The difference between a newsgroup and
a forum is a little vague, but in general forums are used to post messages
and newsgroups are often used to
publish material that can be downloaded by
the newsgroups' members.