Magazines fall into two broad categories: consumer magazines
and business magazines. In practice, magazines are a subset of
periodicals, distinct from those periodicals produced by scientific,
artistic, academic or special interest publishers which are subscription-only,
more expensive, narrowly limited in circulation, and often have
little or no advertising.
Many business magazines are available only, or predominantly,
on subscription. In some cases these subscriptions are available
to any person prepared to pay; in others, free subscriptions are
available to readers who meet a set of criteria established by
the publisher. This practice, known as controlled circulation,
is intended to guarantee to advertisers that the readership is
relevant to their needs. Very often the two models, of paid-for
subscriptions and controlled circulation, are mixed. Advertising
is also an important source of revenue for business magazines.
In publishing or library and information science, the term serial
is applied to materials "in any medium issued under the same
title in a succession of discrete parts, usually numbered (or
dated) and appearing at regular or irregular intervals with no
predetermined conclusion."
A periodical is a type of serial, defined as a "publication
with its own distinctive title, containing a mix of articles ...
by more than one contributor, issued ... at regular stated intervals
of less than a year, without prior decision as to when the final
issue will appear." This includes magazines and journals,
but not proceedings.
Magazines and newspapers are commonly viewed as the most typical
type of periodical (although technically newspapers are not classified
as periodicals in library science). Other serials, periodicals
and journals produced by scientific, artistic, academic or special
interest publishers are often subscription-only, costly, narrowly
limited in circulation, and have little or no advertising. Also
see academic publishing and scientific journals.