YouTube’s iPhone app now supports HDR video, so you’ll get darker blacks and brighter whites when watching videos on your iPhone 12. But what exactly is HDR? Is it worth knowing about? And which apps support it?

HDR stands for High Dynamic Range, but it has nothing to do with those horrible fairytale photos of the same name. It’s a way to capture a wider range of light (and dark) and then play it back. It’s available on HDR TVs, but it’s a fairly new technology for mobile devices. Right now it’s available in the iOS YouTube app, but there are other apps that support it, too.

“If you’re a producer, HDR video can take your work to the next level because it’s simply brighter and more colorful than standard video,” writes Engadget’s Steve Dent, describing an HDR project. “The benefits are more dramatic than 4K, which just provides extra resolution that many people can’t even see.”

If your phone or tablet has an OLED screen, it probably supports HDR video. That’s because OLED has a much better dynamic range than regular LCD screens. LED panels have an always-on panel that lights up behind the grid of LCD pixels. The pixels themselves are nothing more than color filters. When these pixels are turned off, they block out light, making them – supposedly – black. However, light always leaks around the edges or through the pixels, making them less than completely black.