Also called a "supercharger" or "turbocharger." This is a pump which forces air into the cylinders at higher than atmospheric pressure . The increased pressure forces more air into the cylinders than what would be drawn in normally. In this way the engine can burn more fuel and thus produce more power. There are two main types of blowers: the turbocharger, which uses some of the waste heat energy in the exhaust gases to drive a compressor and pump the air; and the belt-driven or shaft-driven supercharger which uses engine power to pump air.