A programmable logic controller (PLC) is an industrial digital computer designed to control manufacturing processes or machinery. It uses a programmable memory to store instructions for specific tasks, allowing it to automate operations such as assembly lines, robotic devices, and other equipment. PLCs are known for their reliability and flexibility, making them essential in various industries. PLCs operate by receiving input signals from sensors and switches, processing the information based on the programmed logic, and then sending output signals to actuators and other devices. This enables real-time control and monitoring of complex systems, enhancing efficiency and safety in industrial environments.