The different parts of a control system first consists of the input value or set point. The controller can consist of a Proportional, Derivative, and or Integral Controller that controls the length of time that the output goes to its set point essentially. The Plant is the actual process or device that is being controlled. The output is being driven to reach the input or set point, and the output is being converted to the necessary units that can be compared with the input signal to lower the difference in the output from the input so the control system can reach its set point.