A motion sensor is an electronic device that is used for motion detection. Motion sensors are a vital component of comprehensive security systems for businesses and homes. An electronic motion detector contains a motion sensor which transforms the detected motion into an electric signal.

A motion sensor contains an electronic sensor which quantifies motion and can either be integrated with or connected to other devices which alert the user of the presence of a moving object that is within the field of view of the sensor.

One advantage of a Motion Sensor is that it saves energy. With a motion sensor light switch, the lights will go on automatically once a person is in its field range. After a certain amount of time, if no further motion is detected, the lights will also turn themselves off automatically. Motion sensors can also provide an additional layer of security and can be paired with security or surveillance cameras or a monitoring system. Another benefit is that they can transmit through walls and ceilings.

Motion sensors are very commonly found in several commercial and domestic applications. They can be found connected to a burglar alarm used in order to alert the security company or home owner after a motion is detected. Motion sensors can also be used to trigger a red light camera. Other applications include motion sensor street lamps, motion-activated outdoor lighting systems and motion sensor lanterns.