Introduction
This is an application for accessing UseNet News (also known as
  NetNews, News, or Discussion Groups). Usenet News is a publicly
  accessible Internet collection of electronic discussion groups
  (called newsgroups), each devoted to a specific topic. There
  are tens of thousands of newsgroups, arranged in a hierarchy
  with each level of the hierarchy separated by a dot (".")
  character. Some of the major hierarchies are "alt" for
  discussion of alternative topics, "comp" for computer topics,
  and "sci" for science topics. From the major hierarchies,
  individual newsgroups or lower hierarchies are formed.
People can read and post articles (also called postings or
  messages) to relevant newsgroups. The people who contribute
  worthwhile postings to newsgroups make the system an invaluable
  resource. Unfortunately, many postings are not of worthwhile
  content, and the "signal to noise" in un-moderated groups can
  be very low.
Navigating Newsgroups
When you first access the Discussions application, you will be
  presented with a listing of the top level UseNet hierarchy,
  from which you can navigate the list of discussion groups. For
  example, if you click on the "plus sign" link to the left of
  the group titled "soc" it will expand into a list of the forums
  and further hierarchies within the "society" hierarchy. The
  name of each newsgroup (such as soc.answers, soc.athiesm, etc.)
  is listed as a link. You can click on the newsgroup names to
  view a list of their posted messages and/or subgroups.
After viewing messages, you can return to this top-level
  listing of newsgroups by clicking on the Browse menu icon at
  the top of the page.
Viewing Articles and Threads
You can view articles in two views: a simple listing of
  postings sorted in some manner, or by threads.
Many newsgroup postings are replies to previous postings. A
  string of successive replies to the same posting forms what is
  called a thread. It is often useful to view messages via such a
  threaded view, so that you can read (or skip) all the messages
  of each subject in sequence. This is especially useful if you
  want to reply to a posting, as threading lets you easily check
  if someone else has already posted the same reply.