A newsgroup begins on a single news server, but is eventually replicated to hundreds or thousands of other servers.
News servers provide the infrastructure that makes newsgroups work.
Each news server has special software that maintains a file for each newsgroup serviced by that server. If your ISP does not have a news server, you can refer to a list of publicly accessible news servers . Once the connection is established, your newsreader downloads all of the new messages posted in the newsgroups that you are subscribed to. You read through the messages and decide to reply to a couple. You also decide to start a new thread with a post of your own.