Definition: A handgun is any firearm meant to be held and fired using one or both hands, with no other bodily contact. Whereas rifles and shotguns feature stocks meant to be rested on the shoulder, and against which one usually lays one's cheek while aiming, handguns are most often held at arm's length when fired.
Handguns include revolvers and pistols, but the terms are not interchangeable. A revolver is not a pistol, and a pistol is not a revolver; pistols and revolvers are simply two varieties of handguns.
