Newsgroups
Many ISP servers host newsgroups. These are discussion groups where people with a common interest can post messages to exchange ideas, thoughts or even to just amuse themselves.

Users subscribe to a newsgroup that interests them and they can then read messages that have been posted and can contribute to the newsgroup by posting their own messages.

Email software or special news reader programs are used to access the newsgroups.

Usenet hosts many thousands of newsgroups. Newsgroups are arranged by topic. Interest topics range from serious discussion groups on politics or technology to groups that contain nothing but mindless drivel.

The names of newsgroups indicate the category and topic. The first part of the name is the category....

Eg. rec.games.computer.quake.playing

(rec = recreation category)

 

It is free to subscribe to a newsgroup - and you can subscribe to many different ones at the same time.

Some newsgroups have their own rules and you should obey them if you post messages.

Messages are posted in threads. A message is posted by a subscriber and any responses to that message are linked into a  thread.