What is a Retina display?

[DavidLux]

Hi, I'm going to buy a device but in its feature show "Retina display", what is it?
Anyone can explain What is the difference between a Retina display or non-Retina?

 

[Nytshade]

Steve Jobs explains it well, every time I try to answer that question I end up getting tons of questions I can't answer hehe... but this video should help

 

[Hassan]

Retina Display is nothing more than high resolution screen technology by Apple which provides resolution levels of 220 to 326 pixels per inch.

 

[web-project]

Retina display is exactly the same as HD display, just apple posh wording.