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LCD vs OLED
Two ways of lighting a pixel, and why one can show true black.
The short version
An LCD screen has a bright light behind it, with a layer of liquid crystals that block more or less of it, pixel by pixel. An OLED screen has no backlight: each pixel makes its own light, and a black pixel is off. It builds on how a screen makes a picture.
I always thought an LED TV was a different kind of screen from an LCD.
It is an LCD, lit by LEDs.
LED is only the name of the light behind it.
Two ways to make light
LCD
Light blockedA backlight shines through liquid crystals that twist to let more or less through. Bright and cheaper.
OLED
Light madeEach pixel is a tiny light-emitting layer. A black pixel is off, so black is truly black.
What it means in practice
An LCD cannot control light at each pixel as precisely as OLED. Light may leak through dark areas, although local-dimming backlights can reduce it by switching groups of LEDs down or off. An OLED switches pixels off, so black is black, and next to a bright pixel the contrast looks striking.
LCDs can be very bright, which helps in a sunny room. OLED materials age with use, and a static image displayed for long periods can cause uneven wear known as burn-in; modern screens use measures to reduce the risk.
Note: names such as QLED and Mini-LED describe improvements to the backlight or colour layers of an LCD. They are still LCDs.
Key takeaways
- An LCD blocks a backlight.
- An OLED pixel makes its own light.
- OLED black is truly off.
- LED TVs are LCDs with LED backlights.
Now you know.
LCD blocks light.
OLED makes light.
LED is only the backlight.
Last reviewed 3 Nov 2026
