A grenade launcher is a weapon that fires a specially designed, large caliber projectile, often with an explosive, smoke, or gas warhead. Today, the term generally refers to a class of dedicated firearms firing unitary grenade cartridges - for example the widely used 40mm type. The most common type are man-portable, shoulder-fired weapons issued to individuals, although larger crew-served launchers are issued at higher levels of organization by military forces.
Grenade launchers are produced in the form of standalone weapons (either single shot or repeating) or as attachments mounted to a parent firearm, usually a rifle. Larger crew-served automatic grenade launchers such as the Mk 19 are mounted on tripods or vehicles.