The servo motor provides a more controlled motion by positioning the shaft to a desired position. In most cases, the shaft is able to travel up to 180°, with a high torque depending on manufacturer. Application is often related to precise movement such as gauges, hatches or steering. The motor is controlled with a Pulse Coded Modulation, which means that a microcontroller must provide appropriate pulses of power to the control pin depending on desired position of the motor. This can be programmed manually with a microcontroller, but the functionality can be handled more easily using a library as seen in the link below.