Motion sensors are devices that detect movement in a specific area. They use various technologies, such as infrared, ultrasonic, or microwave, to sense changes in the environment. When motion is detected, the sensor can trigger an alert, activate lights, or start a security system. These sensors are commonly used in homes, offices, and public spaces for security and automation purposes. There are different types of motion sensors, including passive infrared (PIR) sensors, which detect heat emitted by objects, and active sensors, which emit signals and measure their reflection. Motion sensors are essential for enhancing safety and improving energy efficiency by controlling lighting and other systems based on occupancy.