(The iPhone X.Justin Sullivan/Getty)

Apple announced a slew of new products last Tuesday, including three new iPhones: the iPhone 8, iPhone 8 Plus, and iPhone X.

There are several major differences among the three phones, but one of the biggest changes is the screen — the iPhone X is the first iPhone to feature an OLED screen, while the iPhone 8 and 8 Plus have an LCD screen like Apple's previous phones.

The OLED technology is new for Apple, but anyone who uses Samsung phones (or the Google Pixel, or the new Essential Phone) is already familiar with OLED. In fact, Samsung has been using OLED screens since its first Galaxy phone came out seven years ago.

So what is OLED?

OLED, short for organic light-emitting diode, is a type of display technology. It differs from the more widely used LCD (liquid crystal display) tech by creating light within every pixel that makes up its picture, instead of requiring a separate backlighting system.

This means it can produce perfectly dark blacks. Rather than trying to cover up a backlight behind the scenes and inevitably letting some light through, it shuts off the appropriate pixels. The result is an infinite contrast ratio — i.e., the difference between a display's darkest blacks and brightest whites.

And that, in turn, means an OLED panel can produce a more vivid, realistic picture. If you've ever put a Galaxy S8 and an iPhone 7 side by side, you've seen the difference: Apple's LCD display is excellent, but Samsung's OLED display just pops more. It's more engrossing. It's thinner, too.

I'm simplifying — improved backlighting tech, wider color gamuts, and HDR have helped the best LCD displays catch up a bit. But stuff like that isn't exclusive to LCD. Judged straight up, the contrast difference is enough to make OLED superior.

The drawbacks

OLED isn't perfect. The displays are more prone to color shifting and are very vulnerable to burn-in, meaning that if you leave an image on the screen for too long, you run the risk of it being retained on — or burned into — the screen over time.

This isn't a problem unique to OLED — LCD screens are also susceptible to burn-in. But the vulnerability is greater with OLEDs and could shorten the life span of your phone (though according to some reports, there are clues in the iOS code that Apple has taken special steps to mitigate the burn-in effect on the iPhone X).

(These two screens are displaying the same photo of the color black — that blue line on the OLED screen, right, just serves to show that the screen actually is turned on.Antonio Villas-Boas/Business Insider)