A rocket-propelled grenade or an RPG is the name for any kind of weapon, held on the shoulder that fires rockets that have an explosive warhead. These warheads are attached to a rocket motor and the rocket has fins which help it to fly straight. Some types of RPG are reloadable, while others are used only once and then thrown away. RPGs, with the exception of self-contained versions, are muzzleloaders, loaded from the front end. 