A handgun or pistol is a firearm designed to be held and operated by one hand, with the other hand optionally supporting the shooting hand. This characteristic differentiates handguns as a general class of firearms from their larger counterparts: long guns such as rifles and shotguns (which are held in both hands and usually braced against the shoulder), mounted weapons such as machine guns and autocannons, and larger weapons such as artillery. Some handgun subtypes include single-shot pistols, revolvers, semi-automatic pistols, pepperboxes, and machine pistols.