What is “Retina Display?”
In short “Retina Display” is a term coined by Apple for increasing the quality of graphics so no pixilation can be detected on an image… the details follow:
Retina Display is a brand name used by Apple for liquid crystal displays which they claim have a high enough pixel density that the human eye is unable to notice pixelation at a typical viewing distance. The term is used for several Apple products, including the iPhone, iPod Touch, iPad, and MacBook Pro. As the typical viewing distance would be different depending on each device’s usage, the pixels per inch claimed to be of retina quality can be different for the smallest devices (326, iPhone and iPod Touch), greater than the mid-sized devices (264, iPad) and greater than the larger devices (220, MacBook Pro). When an Apple product has retina display, each user interface widget is doubled in width and height to compensate for the smaller pixels. This mode is referred to as HiDPI mode by Apple. Apple has applied to register the term “Retina” as a trademark in regard to computers and mobile devices with the United States Patent and Trademark Office, Canadian Intellectual Property Office, and in Jamaica. On November 27, 2012 the US Patent and Trademark office approved Apple’s application and Retina® is now a registered trademark.