OLED (Organic Light Emitting Diode) is a solid state device that creates light through thin films made of organic plastics and polymers rather than metals. It was first developed in the 1950s and commercialized in the late 1980s. An OLED has several layers including an emissive layer that produces light when electric current is applied, as electrons combine with holes. OLEDs can be either active or passive, with active using TFT backplanes and suitable for large screens while passive intersect perpendicularly and are best for small screens. OLEDs offer advantages like flexibility, thinness, wide viewing angles and low energy use, but also have challenges including short blue light lifespan and higher production costs compared to