Internet newsgroups are publicly readable by everyone and for the most part publicly writable, although some newsgroups are moderated which means that the postings pass through a human to check for suitability before going out to the whole world.
Basically, an Internet newsgroup is the Internet version of a computerized “bulletin board” where people leave messages, and other people respond to them. There are a few tips before posting to an Internet newsgroup, like double checking that you are not asking a question that has been asked a million times already, otherwise you might be breaking a sacred rule that everyone in the newsgroup lives by.
The other rule of thumb is to always read the newsgroup for a couple of days to get a good feel for it before you start posting to it and read a FAQ if there is one because it may well have all the information you’re looking for. Internet newsgroups exist for almost any subject one might think of, whether it’s serious or just for fun.
Because Usenet cannot be censored at source, some of the newsgroups are inevitably tasteless and offensive to many users. There are many categories of Internet newsgroups: comp- for computers and programming; news- for newsgroups themselves; rec- for sports and hobbies; sci- for scientific research and ideas; talk- for discussion groups; misc- for everything else; and alt- for alternative. Within all these categories, you’ll find a hierarchy of subdivisions that you can continue to research and where you can meet people from all over the world.