In the words of Apple, a Retina display's "pixel density is so high your eye is unable to distinguish individual pixels" at a normal viewing distance.
The display debuted on the iPhone 4, according to The New York Times, and is also available on the iPod and iPhone 4S. "To this day no-one has yet matched that display technology," Phillip W. Schiller, Apple's Senior Vice President of Worldwide Marketing, said at Wednesday's event, according to Engadget's live blog.
The new iPad's resolution is 2,048x1,536 and has 3.1 million pixels, which is, according to Schiller, "The most ever in a mobile device."
Apple touts on its new iPad site that this is four times as many pixels as the iPad 2 and over one million more pixels than an HDTV.
The company explains how its engineers managed to squeeze this many pixels into the device:
You see, every pixel in a display has multiple signals telling it when to light up. But when you have a lot of pixels and a lot of signals on the same plane, signals get crossed and image quality suffers. To make sure everything on the new iPad looks crystal clear, Apple engineers elevated the pixels onto a different plane — separating them from the signals.
Apple also announced that, among other changes, the company has upgraded the camera on the new iPad to a 5-megapixel iSight camera that can record HD video.
The new iPad, which starts at $499 for the 16GB model, will be available on March 16.
Click here for more on the new iPad's features.
Take a look through the slideshow to see some gorgeous new photos of the iPad.