A newsgroup is a depository,
usually within the Usenet system, for messages posted
from many users at different locations. The term
somewhat confusing, because it is usually a discussion
group. Newsgroups are technically different from,
but functionally similar to, discussion forums on
the World Wide Web.
Usenet newsgroups are arranged into Usenet hierarchies,
theoretically making it simpler to find related
groups. The term Top-level Usenet hierarchy refers
to a Usenet hierarchy defined by the prefix prior
to the primary dot. For instance newsgroup rec.arts.sf.starwars.games
would be in the rec.* Usenet hierarchy, where asterisk
(*) is defined as a wildcard character.
are eight most important hierarchies of newsgroups.
Discussion about computer-related topics
Discussion about Usenet itself
Discussion about scientific subjects
Discussion about the humanities (e.g. literature,
Discussion about recreational activities (e.g.
games and hobbies)
Socialising and discussion about social issues
Discussion about contentious issues such as religion
Miscellaneous discussion anything which doesn't
suite in the other hierarchies.
alt.* hierarchy has discussion of all kinds of
topics, and many hierarchies for discussion specific
to a particular geographical area or in a language
other than English.
Typically, a newsgroup is
focused on a particular topic such as 'shellfish'.
Some newsgroups allow the posting of messages
on a wide variety of themes, regarding anything
a member chooses to discuss as on-topic, while
others keep more strictly to their particular
subject, frowning on off-topic postings. The news
admin (the administrator of a news server) decides
how long articles are kept before being expired
(deleted from the server). Usually they will be
kept for one or two weeks, but some admins keep
articles in local or technical newsgroups around
longer than articles in other newsgroups.
Newsgroups are likely to come
in two types, binary and text. There is no technical
difference between the two, but the differentiation
means that users and server who only have limited
facilities can avoid downloading huge binaries.
Newsgroups are greatly like the public message
boards on old bulletin board systems. For those
readers not familiar with this concept, imagine
an electronic version of the corkboard in the
entrance of your local grocery store.
Newsgroups frequently become
cliquish and are subject to sporadic flame wars
and trolling, but they can also be a valuable
source of information, support and friendship,
bring people who are interested in specific subjects
together from around the world.
There are presently well over 100,000 Usenet newsgroups,
but only 20,000 or so of those are active. Newsgroups
differ in popularity, with some newsgroups only
getting a few posts a month while others get several
hundred messages a day.
Web logs have replaced some of
the uses of newsgroups because, for a while, they
were less prone to spamming. A website called
DejaNews began archiving Usenet and also provides
a searchable web interface to it in the 1990s.
Google bought the archive from them and also made
efforts to buy other Usenet archives to attempt
to create a whole archive of Usenet newsgroups
and postings from its early beginnings. Google
also has a web search interface to archive and
also allows newsgroup posting.
Newsgroup servers are hosted
by the various organizations and institutions.
The majority Internet Service Providers hosts
their own News Server or rent access to one, for
their subscribers. Every host of a news server
maintains agreements with other news servers to
frequently synchronize. This way news servers
form a network. When a user posts to one news
server, his message is sent to the servers that
are linked with the one he is connected to, and
from those servers to servers that they are connected
to, and so on.
While Newsgroups were not created
with the purpose of distributing binary files,
they have proven to be quite an effective for
this. Due to the way they work a file uploaded
once will be spread and can then be downloaded
by an unlimited amount of users. More useful is
the fact that each user is drawing on the bandwidth
of their own news server.
Files can be attached to a post,
but very small limit in the size of the file which
can be attached. As such people have come up with
some methods to encode a file into text which
is posted as a post rather then attached to a
post. There is a limit to how large a single post
may be as well, so methods were developed to chain
numerous posts together. The News Client then
cleverly joins the posts and decodes it into a
Two main issues that pose problems
for transmitting binary files over Newsgroups.
The first one is Completion Rates and the other
one is Retention Rates. The business of premium
News Servers is generated mainly on their ability
to offer superior Completion and Retention Rates.