Millions of pixels, individually illuminated
The pixels on an OLED display each contain three sub-pixels. For example, a FHD (1920 x 1080) display has 2,073,600 pixels, which means it has 6,220,800 sub-pixels. Each sub-pixel self-illuminates independently, unlike LCD displays with pixels that need to be backlit, usually by just 50 or 60 LEDs. This means that it’s easier to achieve true black on an OLED display, by simply turning off a pixel. This can’t be done on an ordinary LED display, because the backlight can’t be turned off with such granularity. This fact also gives OLED displays exceptionally high contrast.