Process control simply refers to the control of a process. The main goal of process control is to stabilize process operations in order to consistently produce the desired results, and it can be automatic or manual. In modern processing and manufacturing industries, process control is frequently implemented by automated, computer- based control systems which utilize a number of different "tools." The fundamental building block of these systems is the "process control loop." This module discusses open and closed loop controllers, as well as specific examples of each.