In contrast to mail lists, newsgroups systems resemble bulletin boards; messages are not received as e-mail but are posted in different bulletin boards, more commonly called newsgroups (also called reader news). The onus, therefore, is on the subscriber to go to the newsgroup to see the latest postings. Similar to mail lists, however, newsgroups can be moderated or unmoderated.

The benefit of newsgroups is that, because they are more structured than mail lists, and because it often keeps a threaded archive of postings, it is fairly simple for a user to understand the context and history of discussions. The drawback is that users are often too busy to check for new postings. It is possible, however, to combine the two systems whereby notifications of new postings are sent by e-mail along with a link to the fulltext, which is archived within the newsgroup.

Figure 2: How Newsgroups Work