What forms a vacuum pump inside an engine?

A vacuum pump inside an engine typically consists of a rotor and a housing that creates a low-pressure area as the rotor spins. The rotor's motion draws air out of the engine's crankcase or other areas, creating a vacuum that assists in various functions, such as improving fuel atomization and enhancing the efficiency of the engine's air intake system. In some engines, the vacuum pump is driven by the engine's timing belt or chain, while others may use an electric vacuum pump.