This document discusses motion sensing technology and its various applications. It begins with defining sensors and motion sensors, describing the types of motion sensors including active sensors that emit signals and passive sensors that detect infrared radiation. It then covers motion detection techniques using infrared, optics, radio frequency, sound and vibration. Applications discussed include automated lighting, security systems, and motion sensing in mobile phones and games like the Kinect. The document concludes by noting motion sensing will impact many non-gaming applications.