A running commentary of text messages pertaining to one topic or question. Message threads are used in all forms of user discussions on the Internet, including Usenet newsgroups, Web-based forums, blogs, chat rooms, groupware and email.
The "thread" refers to the collection of messages organized by the software. The messages are displayed in "flat" chronological order by date of posting or in "question-answer" order. The latter is a thread of one question followed by all answers in a hierarchy. Subthreads may also be supported, which enables comments in one of the replies to start another thread that remains linked to the original. See Internet forum