A rocket launcher is a weapon that shoots rockets. Rockets are explosives that fly towards their targets by burning fuel. Some rocket launchers are mounted on a truck, and others are a type of recoilless rifle. Anti-tank guided missiles became commonplace in the late 20th century because they follow their target even if they were not aimed straight at them.
Rockets were invented by the Chinese after they discovered gun powder. In World War II, rocket launchers became powerful enough to destroy tanks.