Originally a peal referred to a set sequence of changes of any length, now more often referred to as a touch. The original meaning is still in use today in call-change ringing. The most famous and frequently rung call change peal, associated with the Devon Association of ringers, is named 60 on 3rds. Related to this meaning is the practice of raising or lowering in peal, that is making the bells ready for change ringing by gradually increasing their swing until each bell is turning through a full circle, and then once ringing has finished returning them to their safe resting position by gradually reducing the amount of swing. A set of bells is sometimes called a peal of bells, but ringers usually prefer the name a ring of bells.
Quarter peals are also commonly rung. These generally meet most of the rules for a peal, but need be only a quarter the length (i.e. at least 1260 or 1250 changes, depending on the number of bells).
For more information please take a look at the Central Council of Church Bell Ringers web site or the list of Peals for Borden Tower using the links below.