Organic Light Emitting Diode works on the same principle as that of a Light emitting Diode which is Electroluminescence.
Which is a result of radiative recombination of Electrons and holes in any Semiconductor Material. These organic LEDs can be classified on several basis such as on the basis of matrix control, on the basis of type of materials used, on the basis of direction in which light exits the surface of OLED,And there several other type of OLEDs such as foldable OLED, Transparent OLED etc.
There are also many methods of manufacturing OLEDs most used of which are inkjet printing and vapor phase deposition etc.
Then finally comes the applications and advantages of this technique. As like LEDs, OLEDs also have a wide area of applications such as in VDUs, PDAs, handheld devices (Like mobile Phones, handheld Gaming consoles), and its future uses include wearable electronics. But as the coin have 2 faces so this technique also have some drawbacks like it is not waterproof and few more which include life time of the device and others.