If you're planning to trade in your old MacBook Air or slot-loading MacBook Pro for a shiny new Apple computer, you're going to see a major difference as soon as you open the lid. All of Apple's latest machines come with a "Retina Display."
What does "Retina" really mean? It's just a fancy way of saying you're getting a Mac with a very high-resolution screen. Not a 4K screen, mind you, or necessarily one of the highest-resolution screens on the market -- simply a screen so dense you can't see individual pixels at a normal viewing distance, which makes text easier to read and images seem crisper.
"It turns out there's a magic number right around 300 pixels per inch, that when you hold something around to 10 to 12 inches away from your eyes, is the limit of the human retina to differentiate the pixels," said Apple CEO Steve Jobs in 2010, when he first introduced the term "Retina Display" to describe the screen of the iPhone 4.
Since the iPhone 4 (326 pixels per inch) in 2010, every one of Apple's products has slowly migrated to Retina Displays, including the iPad (264 ppi), MacBook Pro and iMac (≈220 ppi), and starting in 2015, the 12-inch MacBook (226 ppi) as well. The MacBook Air and 13-inch MacBook Pro (the one with the optical drive) were the only holdouts -- though it looks like the 13-inch MacBook Air is sticking around for now.
Now, Retina is the new normal. It's not special anymore -- but it is a pretty incredible bump in clarity if you haven't experienced it before.
