UsenetUsenet is a giant collection of e-mail serviced topic areas, called newsgroups, that functions like the biggest baddest Bulletin Board System (BBS) in the world. Today, there are over 7,000 newsgroups that together comprise Usenet on topics ranging from abortion to zymurgy.
In the opening words of the Usenet FAQ:
Usenet is a world-wide distributed conferencing and discussion
system. It is available on a wide variety of computer systems
and networks, but the bulk of modern Usenet is transported over
either the Internet or UUCP.
While Usenet is not strictly part of the Internet and the Internet certainly isn't Usenet, for many people, access to Usenet is their main reason for getting on the Internet. You might call Usenet the giant convention center, crossed with the neighborhood bar, for the Internet. It's a gathering place for discussions of everything from physics to postage stamps and politics (both sexual and populist). Through Usenet you can make friends, discuss topics that interest you, and find out answers to almost every imaginable question.
Usenet started out as a small information exchange system between two universities in the late 1970s. The users at those institutions wanted to exchange notes in a loose format, and to organize the information topically. Furthermore, they wanted to make the information available to a whole group of people, rather than individual recipients, as in the case of e-mail delivery. This desire led to the inception of Usenet.
Within a few years it spread to many more universities, and ultimately worked its way into corporations, research labs, the government, and other institutions. During the early 1980s the software underwent a major revision to enable it to handle larger message volumes. This work resulted in the Usenet as we know it today, which extends to sites all over the world, covers thousands of topics, and supports millions of users.
The structure of the Usenet newsgroups is hierarchical, similar to a family tree or an organizational chart--or to the directory structures used in many computer file systems. For this reason, you'll hear some people refer to groups of newsgroups as hierarchies. At the top level, you'll find general topics, and under each of these subdivisions of more and more specific topics. The following graphic illustrates the hierarchical nature of some newsgroups related to the Apple Macintosh, named the comp.sys.mac groups.
Originally, the Usenet newsgroups were divided into seven subgroups, sometimes still known as the Big Seven. New hierarchies have come into being since then, and because every site receives different subsets of the entire Usenet cornucopia, it's impossible to predict which of these you can access. Even so, many sites get all the groups, which means they have to accommodate about 50 MB of incoming data every day!
Here are some of the hierarchies you're most likely to find, with the Big Seven listed first:
Under each hierarchy, the name of the group should become more specific when reading from left to right. If you were looking for a group devoted to pictures of furniture, you'd have to know that alt.binaries is the main image exchange area, and that within the pictures subhierarchy, there's an entry for (you guessed it) furniture!
Knowing how the groups are organized isn't going to help you deal with the huge volumes of information that Usenet can deliver to your electronic doorstep, any time you ask. This is where your newsreader software comes in handy: with a newsreader you can search for groups and keywords within groups and can respond to articles (which is Usenet-speak for an individual posted item on Usenet) with articles of your own.
If you think your comments aren't of general interest to the newsgroup readership, you can send e-mail right from within your newsreader to the author directory instead of posting it to the whole group. Best of all, most good newsreaders keep track of which articles you've already read, so the next time you check the newsgroup, they'll show you only those articles newly arrived since the last time you visited.
Usenet uses the Network News Transfer Protocol (NNTP) to transfer articles and related information. When you use a URL that starts with "news:" you're actually directing your Web browser to seek out the nearest Usenet server (also called a news server) in its domain, and attempt to extract information from the newsgroup specified in that kind of URL. Some browsers have built-in newsgroup handling capabilities (such as Mosaic, Netscape, and Internet Explorer), while others require the assistance of helper applications. This lets you use your Web browser to access Usenet newsgroups without requiring a separate newsreader.