Pulse Width Modulation (PWM) is a technique used to control the amount of power delivered to electrical devices. It works by turning a signal on and off at a rapid pace, varying the duration of the "on" time compared to the "off" time. This method allows for efficient control of devices like motors, lights, and heating elements. PWM is commonly used in various applications, including LED dimming, DC motors speed control, and audio signal processing. By adjusting the duty cycle, which is the ratio of the "on" time to the total cycle time, PWM can effectively manage energy consumption and performance in electronic systems.