LED stands for light emitting diode, so it emits light when sufficient voltage is provided across the LED anode and cathode. Today's LEDs are available in many different types, shapes, and sizes – a direct result of the tremendous improvements in semiconductor technology over recent years. These advancements have led to better illumination, longer service life, and lower power consumption. They've also led to more difficult decision making, as there are so many types of LED to choose from.
LEDs can be categorized into miniature, high power, and application-specific LEDs:
Miniature LEDs: These LEDs are extremely small and usually available in a single color/shape. They can be used as indicators on devices such as cell phones, calculators, and remote controls.
High power LEDs: Often referred to as high output LEDs, these are a direct result of improved diode technology. They offer a much higher lumen output than standard LEDs. Typically, these LEDs are used in car headlights.
Applicatio n-specific LEDs: As the name suggests, there are many LEDs that fall under this category. These are flash LEDs, RGB LEDs, seven segment display, LED lamps, and LED bars.