Light-emitting diode
LEDs are used in many places. Early LEDs could only emit infrared, and were used in optical fiber communication. Later ones were used as red indicator lights on many electronic devices, and in the 1980s they also made other colors. In the 21st century they are used for bright advertising signs, brake lights on cars, in TVs, and more recently, light bulbs for the home. White LEDs bright enough to illuminate rooms are usually more expensive than regular lightbulbs but they last longer and burn less electricity.