What is a key characteristic of a Light Emitting Diode (LED)?

A key characteristic of a Light Emitting Diode (LED) is that it emits light when connected in the forward direction. This occurs because an LED is a type of diode that only allows current to flow in one direction, and under these conditions, it uses the energy from the electrical current to excite electrons in a semiconductor material. When these electrons return to their normal state, they release energy in the form of light.

This characteristic enables LEDs to be more efficient and longer-lasting compared to traditional light sources that rely on filaments or gas. In contrast, relying on reverse current flow does not produce light in LEDs, and they do not require high voltage; they are designed to operate at relatively low voltages, which is a significant advantage for many electronic applications.