What is servo?

A servo is a small device with an output shaft. The axis can be positioned to a specific angular position by sending a servo-encoded signal. As long as there is an encoded signal in the input line, the servo will maintain the angular position of the axis. As the change of the encoded signal, the angular position of the axis change. In practice, servo systems are used in radio-controlled aircraft to locate control surfaces such as elevators and rudders. They are also used in radio-controlled cars, puppets, and of course, robots.