The newsgroups are part of a worldwide distributed network that was first started way back in 1979. There are thousands of decentralized and independent machines loosely held together with the NNTP (News Networking Transfer Protocol). These machines, also called news servers, are what store the newsgroups and their messages. The words "Usenet" and "newsgroups" are often times used interchangeably. But it should be noted that the term Usenet represents the whole of the community, while the newsgroups are the individual repositories where all the magic happens. Here's how it's all broken down:
The Newsgroups are organized hierarchically. There are eight (8) well known top-level hierarchies that help identify newsgroups that share the same prefix: comp.*, humanities.*, misc.*, news.*, rec.*, sci.*, soc.*, and talk.*. These top-level hierarchies are known as the "Big 8". The Big 8 were actually the Big 7 when they were launched during the "Great Renaming" in 1987. The humanities.* hierarchy was added in 1995.
These top-level hierarchies are representative of only a small number of total hierarchies - there are many thousands of other top-level hierarchies. The difference has nothing to do with popularity; instead, the Big 8 hierarchies are guided by a management board
which administers the creation and deletion of newsgroups within these hierarchies. The management board that governs these hierarchies have no influence over the rest of the Usenet newsgroups.
These 8 hierarchies, or categories, can be broken down further to distinguish individual newsgroups. Take for example the news.announce.important newsgroup. All the newsgroups that belong to the news.* hierarchy share this prefix. What distinguished one newsgroup from the next is the information that comes after, so in other words news.announce.important is a completely different newsgroup from news.admin.misc.
So what goes on in these newsgroups? You name it. Discussions range from just about every topic imaginable. Sure, there's plenty of spam and other nonsense, but there's also some very valuable information on computers, automotive repair, programming, life, sex, drugs, and rock n' roll. The sky's the limit when it comes to the newsgroups and the discussions you can find there. We recommend checking out some of the newsgroups in the rec.* hierarchy and read some of the digital lunacy that goes on.
The alt*. hierarchy prefix is a realm that belongs to no one. There is no management board and just about anything goes. This hierarchy was developed just after the Great Renaming, with the intentions that it would be used for alternative discussions that didn't belong anywhere else. While it's true that many oddball newsgroups belong to the alt.* hierarchy, it's typically associated with the alt.binaries - one of the most popular second-level hierarchies. This second-level hierarchy is reserved for posting binary files. But there's a wide variety of topics available on the alt.* hierarchy, not just the binaries. Looking for an eye opening experience? Check out the alt.sex newsgroups.