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.
Usenet is distributed among a large, constantly changing conglomeration of servers that store and forward messages to one another in so-called news feeds.
Individual users may read messages from and post messages to a local server operated by a commercial usenet provider, their Internet service provider, university, employer, or their own server.
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.
Usenet resembles a bulletin board system (BBS) in many respects and is the precursor to Internet forums that are widely used today.
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.
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 blue, green, and red dots on the servers represent the groups they carry.