What they are Usenet is a set of bulletin boards or newsgroups made available via the Internet.
People can choose to write on a new topic, or to post a followup on an existing topic.
The combination of the original article and all its subsequent followups is known as a thread . All news-reading software allows you to read news by thread, and to choose to follow or ignore particular threads. Newsgroup hierarchies Newsgroups are organised into a fairly loose set of hierarchies. There are a number of standard hierarchies, and any number of local hierarchies, for example most of the main ISPs have their own groups, some of which are made publicly available. The current list of newsgroups stands at around 17,000.