The 360 Degree Rotary Encoder Module is a rotary input device that provides an indication of how much the knob has been rotated and what direction it is rotating in. It’s a great device for stepper and servo motor control.  You could also use it to control devices like digital potentiometers.

This 360 Degree Rotary Encoder is also an incremental electro-mechanical device that converts the angular position or motion of a shaft or axle to digital code. The output of incremental encoders provides information about the motion of the shaft, which is typically further processed in processor/controllers into information such as speed, distance, and position.