A collection of posted messages on a Network News Transfer Protocol (NNTP) server. Newsgroups contain postings on a particular topic, although they are often a prime target for spammers who post unsolicited advertisements. Newsgroups are defined hierarchically using a dotted notation. An example of a newsgroup is alt.books.computing, which is an “alternative” group that discusses books about computing. The dotted notation of the newsgroup name emphasizes the hierarchical structure of the Usenet system of newsgroups. For example,
Newsgroups can be either moderated or unmoderated. In moderated newsgroups, all messages posted to the newsgroup are first sent to the newsgroup moderator, who accepts or rejects messages depending on their relevance to the group’s focus. Unmoderated groups are generally a free-for-all, although politeness dictates that users post only messages related to the newsgroup’s focus.
When you first join a newsgroup, it’s a good idea to “lurk” in the background for a while and read the postings to understand the focus and tone of the group. Posting off the topic or at too low a level in an advanced group can lead a “newbie” to get flamed.