Some handguns are single-shot, but most have either
a magazine, in the case of a semi-automatic, or a cylinder, in the case
of a revolver.
Revolvers come in either single or double action. A
single-action revolver must be manually cocked first, then the trigger
is squeezed before it can fire. A double-action revolver is cocked and
fired in one motion when the trigger is squeezed.
