Light-emitting devices are electronic components that produce light when an electric current passes through them. Common examples include light-emitting diodes (LEDs) and laser diodes. These devices are widely used in various applications, such as displays, indicators, and lighting solutions, due to their energy efficiency and long lifespan. The principle behind light-emitting devices is electroluminescence, where materials emit light in response to an electric field. LEDs are particularly popular because they consume less power and generate less heat compared to traditional incandescent bulbs. This makes them ideal for use in everything from household lighting to television screens.