How Newsgroups Work

Along with e-mail, newsgroups are one of the oldest communication methods on the Internet. But there are many ways to communicate on the Web. You probably use more than one method, depending on your needs. One method you might use is:

Newsgroups - a newsgroup is a continuous public discussion about a particular topic. Newsgroups are decentralized, which means that the messages are not maintained on a single server, but are replicated to hundreds of servers around the world.

Newsgroups are most effective when:

You don't need an immediate answer.
You want to communicate with more than one person.
You want to communicate with a group of people interested in the same topic.
You need or want to provide extensive information about that topic.

The Newsgroup Process

A newsgroup begins on a single news server, but is eventually replicated to hundreds or thousands of other servers. News servers provide the infrastructure that makes newsgroups work. Each news server has special software that maintains a file for each newsgroup serviced by that server.

Here's what happens when you access a newsgroup:

Your newsreader,availabler from our newsreader page. (Microsoft's Outlook Express contains a newsgroup client.) using NNTP, connects to the news server designated in your configuration. Typically, the news server's connection information is provided by subscribing to our Usenet service.
Once the connection is established, your newsreader downloads all of the new messages posted in the newsgroups that you are subscribed to.
You read through the messages and decide to reply to a couple. You also decide to start a new thread with a post of your own.

Replying to a post in a newsgroup is as easy as replying to an e-mail.
Your newsreader sends your messages to the news server. (If it's an offline newsreader, it must first reconnect to the news server via NNTP).
The news server saves your messages in the file for that newsgroup. Newsgroup files are large text files, meaning that each new message is simply appended to the end of the text file. As the file reaches a certain size, or after a certain length of time, the messages at the beginning of the file are removed and placed in a newsgroup-archive text file.
The news server connects to one or more other news servers using NNTP (or UUCP) and sends the updated information. Each news server compares its own file for the newsgroup with the files it receives for that same newsgroup. It adds any differences that it finds -- this is important, because if the news server simply saved the received file over the one it already had, it would lose any messages posted to it during the update. By comparing the files, it can extract the new messages and add them to the file it has, without losing any new postings. The news server then sends the combined file to the other news servers.
The newsgroup changes are replicated to each news server until all of them have the updated information. This process is ongoing, and most large newsgroups change so quickly that the updating is virtually continuous.
Other subscribers read your messages, plus all the others posted since the last time they looked at the newsgroup, and reply.
You see their replies and new messages, and the process repeats.

What are newgroups?

Note that the correct term is "newsgroups"; they are not called areas,bases, boards, bboards, conferences, round tables, SIGs, echoes, rooms or usergroups! Nor, as noted above, are they part of the Internet, though they may reach your site over it. Furthermore, the people who run the news systems are called news administrators, not sysops. If you want to be understood, be accurate.

A newsgroup is a discussion about a particular subject consisting of notes written to a central Internet site and redistributed through Usenet, a worldwide network of news discussion groups. Usenet uses the Network News Transfer Protocol (NNTP).

Newsgroups are organized into subject hierarchies, with the first few letters of the newsgroup name indicating the major subject category and sub-categories represented by a subtopic name. Many subjects have multiple levels of subtopics. Some major subject categories are: news, rec (recreation), soc (society), sci (science), comp (computers), and so forth (there are many more). Users can post to existing newsgroups, respond to previous posts, and create new newsgroups.

Newcomers to newsgroups are requested to learn basic Usenet netiquette and to get familiar with a newsgroup before posting to it. The rules can be found when you start to enter the Usenet through your browser or an online service. You can subscribe to the postings on a particular newsgroup.

Some newsgroups are moderated by a designated person who decides which postings to allow or to remove. Most newsgroups are unmoderated.

Usenet is the set of people who exchange articles tagged with one or more universally-recognized labels, called "newsgroups" (or "groups" for short).
There is often confusion about the precise set of newsgroups that constitute Usenet; one commonly accepted definition is that it consists of newsgroups listed in the periodic "List of Active Newsgroups" postings which appear regularly in news.lists.misc and other newsgroups. A broader definition of
Usenet would include the newsgroups listed in the article "Alternative Newsgroup Hierarchies" (frequently posted to news.lists.misc). An even
broader definition includes even newsgroups that are restricted to specific geographic regions or organizations. Each Usenet site makes its own decisions about the set of groups available to its users; this set differs from site to site.

http://www.faqs.org/faqs/usenet/what-is/part1/

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