Handguns can be classified by their action type. The action of a handgun is made up of parts that load, unload, fire, and eject the cartridge. Actions are either single-shot or repeating styles. Single-shot handguns (single-shot pistols) must be reloaded each time the handgun is fired. Repeating handguns (revolvers and semi-automatic pistols) have extra cartridges ready in a magazine or cylinder.