The presence of an object is detected by proximity sensors, which are non-contact sensors. Different approaches, such as optical, can be used to create proximity sensors (like infrared or Laser ). aural (Ultrasonic). Electrifying (Half Effect) Sensor of Inductive Proximity Mobile phones, cars (parking sensors), industries (object alignment), and ground proximity in airplanes are some of the applications of proximity sensors. ADD ON THIS WRITTING 75 MORE WORDS , TALK ABOUT THE TOPIC IN GENERAL THE TOPIC IS "PROSIMITY SEMSORS"