 Missile, in modern language. The missile, also known as a guided missile, is a guided self-propelled system, as opposed to an unguided self-propelled munition, referred to as a rocket although these two can also be guided. Missiles have four system components, targeting or missile guidance, flight system, engine, and warhead. Missiles come in types adapted for different purposes, surface-to-surface and air-to-surface missiles ballistic, cruise, anti-ship, anti-tank, etc. surface-to-air missiles and anti-ballistic air-to-air missiles and anti-satellite weapons. All known existing missiles are designed to be propelled during powered flight by chemical reactions inside a rocket engine, jet engine, or other type of engine.Citation needed non-self-propelled airborne explosive devices are generally referred to as shells and usually have a shorter range than missiles. In ordinary British-English usage predating guided weapons, a missile is such as objects thrown at players by rowdy spectators at a sporting event.