A programmable logic controller (PLC) is a small, sturdy industrial computer designed for control of automated industrial processes and machines. PLCs are used almost everywhere. They are most frequently used in factories and industrial plants to control pumps, motors, lights, circuit breakers, fans, and other machinery. In everyday life, these controllers are utilized in elevators, automatic car washes, traffic signals, amusement park rides, among other equipment that we otherwise take for granted.