Organic Light Emitting Diode is a scalable nano level emerging technology in Flat Panel Displays and as a White Light Source with efficient features. This paper focuses on OLED structure, principle aspects, fabrication methodology and different techniques to replace current white light sources like Incandescent bulbs, Fluorescent tubes, and even display techniques like Liquid Crystal Displays, Plasma technologies. OLEDs can be fabricated using Polymers or by small molecules. OLED matrix displays offer high contrast, wide viewing angle and a broad temperature range at low power consumption. These are Cheaper, Sharper, Thinner, and Flexible. OLEDs have a potential of being white-light sources that are OLEDs are energy conversion devices (electricity-to-light) based on Electroluminescence. Electro-luminescence is light emission from a solid through which an electric current is passed. OLEDs are more energy-efficient than incandescent lamps. The luminous efficiency of light bulbs is about 13 - 20 lm/W but the latest experimental green emitting OLEDs already have luminous efficiency of 76 lm/W, though at low luminance. The development is on track for OLEDs to effectively compete even with fluorescent lamps, which have the luminous efficiency of 50 - 100 lm/W. One big advantage of OLEDs is the ability to tune the light emission to any desired color, and any shade of color or intensity, including white. Achieving the high Color Rendition Index (CRI) near 100 (the ability to simulate the most pleasing white color, sunlight), is already within the reach of OLEDs. Another advantage of OLEDs is that they are current-driven devices, where brightness can be varied over a very wide dynamic range and they operate uniformly, without flicker.