A torque converter is a type of fluid coupling that transfers rotating mechanical power from a source, like an engine, to a rotating driven load. It's commonly used in automatic transmissions in vehicles. It works by using transmission fluid to transmit power. A pump, driven by the engine, circulates fluid. This fluid then spins a turbine, which is connected to the transmission's output shaft. A stator redirects fluid flow to multiply torque when there's a significant speed difference between the pump and turbine.