What Are News Groups?
News groups are basically forums, but instead of being on the http protocol they are on usenet. News groups are categorized by their content.
With the way usenet works, you have to download all the header files of a newsgroup, then you can download the actual content in the header with your newsreader.
Once you get the hang of it you can see that usenet is full of discussions that are very similar to discussions that take place primarily on forums today. HTTP links to news items or full text posts can be found in many usenet news groups along with comments.
To get a general idea, check out Google Groups.
For binary news groups, refer to my other posts below.