In a modern military, a missile is a self-propelled guided weapon system. Missiles have four system components: targeting and/or 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), surface-to-air missiles (anti-aircraft and anti-ballistic), air-to-air missiles, and anti-satellite missiles. An ordinary English-language usage predating guided weapons is simply any thrown object, such as items thrown at players by rowdy spectators at a sporting event.
Contributions by Marcus Qwertyus, Jellyfish dave, and ClueBot.