A handgun is a firearm designed to be held and operated by one hand. This characteristic differentiates handguns as a general class of firearms from long guns such as rifles and shotguns (which are mounted against the shoulder).Some handgun subtypes include derringers, single-shot pistols, revolvers, semi-automatic pistols, pepperboxes, and machine pistols.The overlapping variations in meaning of the words "pistol" and "handgun" are discussed below.