PID stands for Proportional-Integral-Derivative, which is a type of control loop feedback mechanism widely used in industrial control systems. It helps maintain a desired output by adjusting the input based on the difference between the desired setpoint and the actual process variable. The three components—Proportional, Integral, and Derivative—work together to minimize error and improve system stability. In a PID controller, the Proportional part responds to the current error, the Integral part addresses past errors by accumulating them over time, and the Derivative part predicts future errors based on the rate of change. This combination allows for precise control in various applications, such as temperature regulation and speed control in machinery.