the formation and instantaneous collapse of innumerable air or vapor pockets (or bubbles) in flowing liquids due to the hydrodynamic generation of rapid and intense pressure changes. This may result from the movement of a solid body, such as a propeller blade or piston. Cavitation can also occur in a hydraulic system as a result of low fluid levels that draw air into the system, producing tiny bubbles that undergo explosive decompression at the pump outlet.