We all know what a sensor is, right? A sensor makes "sense" of physical property - it turns something about the physical world into data upon which a system can act. Sensors are used today almost everywhere. You can find different types of sensors in our homes, stores, cars, etc. Smoke detectors may use a smoke sensor to detect smoke or fire, a burglar alarm may use ultrasonic sound waves that bounce off moving objects, radar guns bounce microwaves off moving cars. Others still, may detect pressure (barometers) or one’s heart rate (e.g. smart wristband). All these and many other automation tasks are possible because of sensors. Just select a suitable sensor for your product then sense the world!