# OLED

> A screen where every pixel makes its own light, so black is truly off.

- Level: Basic
- Topics: Hardware
- URL: https://tidbit.legios.com.ar/oled/
- In Spanish: [OLED](https://tidbit.legios.com.ar/es/oled/)

Most screens for years were LCDs: a white light shines from behind, and a layer of tiny shutters lets more or less of it through each colored pixel. An **OLED** (organic light-emitting diode) screen works differently. Each pixel is made of a material that glows by itself when electricity runs through it. There is no backlight at all.

That changes a lot. A black pixel on an OLED is just switched off, so blacks look truly black, even in a dark room, and contrast is very high. Screens can be thinner and even bend, which is how foldable phones exist. And a dark background actually saves battery, because off pixels use no power. Most high-end phones, many smartwatches and a growing number of TVs and laptops use OLED; Samsung calls its version **AMOLED**.

The trade-offs: OLED is more expensive to make, and the glowing material slowly wears out with use. If the same bright image stays in the same place for a very long time, like a TV channel logo, it can leave a faint permanent ghost, called **burn-in**. Modern screens shift pixels and dim static elements to make that rare.

## An analogy

An LCD is a stained-glass window with one big lamp behind it: to show black, it has to block the lamp, and a little light always leaks. An OLED is a stadium crowd holding phone flashlights: each person can turn theirs on, change its color, or just turn it off.

## Keep in mind

- Each pixel produces its own light; there is no backlight.
- True blacks and very high contrast, because black pixels are off.
- Thinner and flexible, which makes foldable phones possible.
- Can suffer burn-in if a bright static image stays on for very long.

## Go deeper

- [OLED on Wikipedia](https://en.wikipedia.org/wiki/OLED)

## Related terms

- [Lithium-ion battery](https://tidbit.legios.com.ar/lithium-ion-battery/): The rechargeable battery inside phones, laptops and electric cars.
- [Wearables](https://tidbit.legios.com.ar/wearables/): Small computers you wear on your body, like smartwatches, fitness bands and smart rings.
- [Laptop](https://tidbit.legios.com.ar/laptop/): A whole computer folded into one portable case that runs on a battery.
- [Samsung](https://tidbit.legios.com.ar/samsung/): Korean giant that sells phones and TVs, and makes much of the world's memory chips.