Network news evolved out of mailing lists that allowed a group of people with common interests to share information. The network news system is a central clearing house for these messages. Instead of mailing a message to everyone on the list, you post it to a newsgroup. The news software will store the message in the newsgroup on your local network, and also exchange postings generated at your site with postings from other sites. When people want to read the latest news, they use a news reader to find messages that have been posted since the last time they checked the newsgroup.
Mailing lists are still common, especially for small, specialized groups.
An example of a mailing list that recently became a full newsgroup is the group for users of FrameMaker, a word processing system for Unix systems and personal computers. The mailing list was named framers . When the list grew to a few hundred members, a vote was taken, and the group applied to have a newsgroup formed. Now people who would like to share information about FrameMaker subscribe to the newsgroup named comp.text.frame . As the previous example shows, newsgroups names are hierarchical and resemble domain names.