A semiconductor that emits light when current is passed through it. LEDs are very efficient and are used in many household items including light bulbs and television screens.

A sound sensor outputs a signal based on the amount of ambient noise that is present. The Sound Sensor is programmed using a value between 0 and 100, where 0 is the soft sound that can be detected and 100 is the loudest.

A Position Servo will turn to a specific angle from 0 to 180 degrees and could be used to open and close a door. A Rotation Servo will rotate continuously and could be used to spin the blades of a fan.

Often called an Ultrasonic Sensor, a distance sensor detects distance by transmitting and receiving ultrasonic tones.

The sensor determines the distance to an object by measuring the time lapse between transmitting and signal and receiving it back.