Quick Answer: An organic light-emitting diode, also known as organic electroluminescent diode, is a type of light-emitting diode in which the emissive electroluminescent layer is an organic compound film that emits light in response to an electric current. This organic layer is situated between two electrodes; typically, at least one of these electrodes is transparent. OLEDs are used to create digital displays in devices such as television screens, computer monitors, and portable systems such as smartphones and handheld game consoles; its significant advantage over liquid-crystal displays is that the individual pixels emit their own light, requiring no backlight like LED-lit LCDs. OLEDs are fundamentally different from LEDs and do not employ a crystalline structure. There are two main families of OLED: those based on small molecules and those employing polymers. Adding mobile ions to an OLED creates a light-emitting electrochemical cell which has a slightly different mode of operation.