Automatic train control (ATC) is a system designed to enhance the safety and efficiency of train operations. It monitors the train's speed and position, automatically adjusting the throttle and brakes to maintain safe travel limits. This helps prevent accidents caused by human error, such as speeding or running signals. ATC systems can vary in complexity, with some providing basic speed control while others offer advanced features like automatic train protection (ATP) and automatic train operation (ATO). These technologies work together to ensure trains operate smoothly, reducing delays and improving overall service reliability for passengers.