This article is from the Theatre FAQ, by aku@leland.Stanford.EDU (Andrew Chia-Tso Ku) with numerous contributions by others.
The term The Fringe covers all the other theatres in and around London.
It is of wildly varying quality, but much of it is quite good, and the
prices are generally lower. Some Fringe theatres are run as clubs,
which means they are covered by somewhat different regulations than
normal theatres. In most cases, this just means that if you aren't
already a member you have to pay an extra pound or two to join the club
when you buy a ticket. Many of the clubs have reciprocal memberships,
so if you go to several different Fringe theatres you may only have to