From Fan History Wiki
Usenet is generally perceived to be a distributed discussion system. A Usenet or the Usenet is the set of people who exchange articles tagged with one or more universally-recognized labels, called "newsgroups". It functions partially like a mailling list and partially like a bulletin board system depending on the configuration of the group, although it predates both forms of online discussion.
The distribution is server based through a network of subscribed users submitting articles on a common forum topic. The web-based part of the system are usually archives for already distributed messages.