A torque converter is a type of fluid coupling used in automatic transmissions to transfer power from the engine to the wheels. It allows the engine to keep running while the vehicle is stationary, enabling smooth acceleration without stalling. The device uses hydraulic fluid to transmit torque, which helps in multiplying the engine's power during acceleration. Inside the torque converter, there are three main components: the impeller, turbine, and stator. The impeller is connected to the engine, while the turbine is linked to the transmission. As the engine spins, the impeller pushes fluid to the turbine, causing it to rotate and ultimately drive the vehicle forward.