Step motor can be regarded as motor without commutator. Typically, all windings in the motor are part of the stator, and the rotor can be a permanent magnet, or in the case of a variable reluctance motor, it can be a toothed block of some soft magnetic material. All commutation must be handled externally by the motor controller. Generally, the motor and controller are designed to keep the motor in any fixed position and rotate in one or two directions. Most steppers, because they are also known, can step on audio, allowing them to rotate quickly, and with the right controller, they can "start" and "stop" in a controlled direction.