As is the case with e-mail, there are dozens of ways to interact with network newsgroups, and rather than explain one system here we will just give a broad overview of what newsgroups are and encourage you to learn about the newsreader software available on your local network.
Network news evolved out of mailing lists that allowed a group of people with common interests to share information. For example, if 20 people at different sites were all doing research on plankton layers in the ocean, each one could install a ``mail alias'' on their system so they could easily send mail to all their colleagues at once. A command of the form
% mail plankton-lovers < msg1would have the system mail the file msg1 to everyone on the mailing list named plankton-lovers. As the mailing list grows, however, there are two drawbacks to this approach: the e-mail system becomes needlessly overloaded when it sends the same message to several hundred users (many of whom might be at the same site), and users will be flooded with mail as more and more people start to send messages to the group.