A stepper motor has a dual H-bridge topology allowing control of the current intensity in each coil. That allows creation of a magnetic field in any desired direction and the shaft of the motor aligns with this magnetic field. When the shaft turns 90°, it is called a step. The 90 degrees is valid for a permanent magnet stepper motor. On the market, the most common stepper motors are called hybrid, and by design, the step is 1.8 degree/step instead of 90 degree. An intermediate step within a step is called microstep. For instance, if the current has sixteen different values, the shaft can take sixteen different positions and it is said the motor is driven in sixteen microsteps. This topology allows the user to control the strength and direction of the magnetic field.