Usenet was conceived in 1979 and publicly established in 1980, at the University of North Carolina at Chapel Hill and Duke University, over a decade before the World Wide Web went online and the general public received access to the Internet, making it one of the oldest computer network communications systems still in widespread use. It was originally built on the "poor man's ARPANET", employing UUCP as its transport protocol to offer mail and file transfers, as well as announcements through the newly developed news software such as A News. The name Usenet emphasized its creators' hope that the USENIX organization would take an active role in its operation.
The articles that users post to Usenet are organized into topical categories known as talk.atheism are in the talk.* hierarchy. When a user subscribes to a newsgroup, the news client software keeps track of which articles that user has read.
In most newsgroups, the majority of the articles are responses to some other article. The set of articles that can be traced to one single non-reply article is called a thread. Most modern newsreaders display the articles arranged into threads and subthreads.
When a user posts an article, it is initially only available on that user's news server. Each news server talks to one or more other servers (its "newsfeeds") and exchanges articles with them. In this fashion, the article is copied from server to server and should eventually reach every server in the network. The later peer-to-peer networks operate on a similar principle, but for Usenet it is normally the sender, rather than the receiver, who initiates transfers. Usenet was designed under conditions when networks were much slower and not always available. Many sites on the original Usenet network would connect only once or twice a day to batch-transfer messages in and out. This is largely because the POTS network was typically used for transfers, and phone charges were lower at night.
The format and transmission of Usenet articles is similar to that of Internet e-mail messages. The difference between the two is that Usenet articles can be read by any user whose news server carries the group to which the message was posted, as opposed to email messages, which have one or more specific recipients.
Today, Usenet has diminished in importance with respect to Internet forums, blogs and mailing lists. Usenet differs from such media in several ways: Usenet requires no personal registration with the group concerned; information need not be stored on a remote server; archives are always available; and reading the messages requires not a mail or web client, but a news client. The groups in alt.binaries are still widely used for data transfer.