Terminology
===========

"news"
     This is what you are supposed to use this thing for--reading news.
     News is generally fetched from a nearby NNTP server, and is
     generally publicly available to everybody.  If you post news, the
     entire world is likely to read just what you have written, and
     they'll all snigger mischievously.  Behind your back.

"mail"
     Everything that's delivered to you personally is mail.  Some
     news/mail readers (like Gnus) blur the distinction between mail
     and news, but there is a difference.  Mail is private.  News is
     public.  Mailing is not posting, and replying is not following up.

"reply"
     Send a mail to the person who has written what you are reading.

"follow up"
     Post an article to the current newsgroup responding to the article
     you are reading.

"backend"
     Gnus gets fed articles from a number of backends, both news and
     mail backends.  Gnus does not handle the underlying media, so to
     speak--this is all done by the backends.

"native"
     Gnus will always use one method (and backend) as the "native", or
     default, way of getting news.

"foreign"
     You can also have any number of foreign groups active at the same
     time.  These are groups that use different backends for getting
     news.

"secondary"
     Secondary backends are somewhere half-way between being native and
     being foreign, but they mostly act like they are native.

"article"
     A nessage that has been posted as news.

"mail message"
     A message that has been mailed.

"message"
     A mail message or news article

"head"
     The top part of a message, where administrative information (etc.)
     is put.

"body"
     The rest of an article.  Everything that is not in the head is in
     the body.

"header"
     A line from the head of an article.

"headers"
     A collection of such lines, or a collection of heads.  Or even a
     collection of NOV lines.

"NOV"
     When Gnus enters a group, it asks the backend for the headers of
     all unread articles in the group.  Most servers support the News
     OverView format, which is more compact and much faster to read and
     parse than the normal HEAD format.

"level"
     Each group is subscribed at some "level" or other (1-9).  The ones
     that have a lower level are "more" subscribed than the groups with
     a higher level.  In fact, groups on levels 1-5 are considered
     "subscribed"; 6-7 are "unsubscribed"; 8 are "zombies"; and 9 are
     "killed".  Commands for listing groups and scanning for new
     articles will all use the numeric prefix as "working level".

"killed groups"
     No information on killed groups is stored or updated, which makes
     killed groups much easier to handle than subscribed groups.

"zombie groups"
     Just like killed groups, only slightly less dead.

"active file"
     The news server has to keep track of what articles it carries, and
     what groups exist.  All this information in stored in the active
     file, which is rather large, as you might surmise.

"bogus groups"
     A group that exists in the `.newsrc' file, but isn't known to the
     server (i. e.,  it isn't in the active file), is a *bogus group*.
     This means that the group probably doesn't exist (any more).

"server"
     A machine than one can connect to and get news (or mail) from.

"select method"
     A structure that specifies the backend, the server and the virtual
     server parameters.

"virtual server"
     A named select method.  Since a select methods defines all there
     is to know about connecting to a (physical) server, taking the who
     things as a whole is a virtual server.