Electronic Sensors
Electronic Sensors is a group of devices that detect things like light or touch and send signals to a machine.
Think of it this way
A smoke detector on the kitchen ceiling watches for tiny smoke bits in the air. When smoke reaches it, the detector sends a signal to sound the alarm. A motion-sensing light above the stove works the same way. It spots movement and sends a signal to flip the light on.
Explaining electronic sensors by grade level
Think about a smoke alarm in your home. It has a tiny part inside that can sense smoke in the air. When it senses smoke, it makes a loud beep. That tiny part is a sensor, and it works using power from a battery.