The difference between a pistol and a revolver lies in two features of these handguns: the chamber and the action. In a pistol, the chamber is built into the gun barrel as one integral piece, whereas in the revolver it is contained in a multi-chambered revolving cylinder, which is separated from the barrel. Whether it is single or double, the revolver action is mechanically determined by a pawl that rotates the cylinder each time the hammer is cocked as each one of its chambers is aligned with the gun barrel with a click just before firing, with the cylinder revolving around a central axle or pin; thus, this sidearm’s revolving action is triggered by the forefinger squeezing the revolver trigger (as in a double-action system) or by manually cocking back the hammer before squeezing the trigger (as in a single-action mechanism). On the other hand, a pistol auto-loading mechanism depends on the cartridge ignition, which causes the gun slide recoil, triggering the automatic extraction and feeding. A revolver is a repeating firearm, but a pistol is a semi-automatic sidearm, whose rate of fire is higher than that of a revolver and whose magazine usually holds more cartridges than the cylinder. Thus, it is preferred over the revolver in combat situations, being part of a modern army’s armament.