Because the term retina display does not apply to a specific technology, Apple has used it for different displays with very different pixel densities. It was first used in the iPhone 4, which has 326 pixels per inch, and then on the iPad 2, which boasts a much lower pixel density of only 264 pixels per inch, making it quite easy for most people to distinguish pixels at normal viewing distance. If we follow Apple’s own definition of retina display then it follows that most modern smartphones from any brand are using the technology.

Due to the retina display’s high resolution, it makes any font size clearer and easier to read. The high resolution apple products are known for is made possible a result of a number of factors:

• There is a higher contrast ratio compared to older models, making the black and white in an image more distinguishable.
• LED backlights and chemically treated glass screens boost image quality.
• There is a greater density of pixels used on the screen.
• In-plane switching (IPS) provides better viewing angles.