What Are Pixels?

• Essentially, pixels are dots. The images, including text, on your screen are composed of these dots, which your eye blends together into smooth images. When images are viewed at normal size, your mind does not translate the dots because they are so close together they appear to be the same image. When you magnify that image, the dots become apparent. With a retina display, the pixels are smaller, so there are more of them packed into every square inch of the display. When you magnify a portion of the screen, there are still enough dots to create an apparently smooth image, giving you a lack of "pixilation" or rough edges because your mind does not interpret the individual dots.
  
  

IPad Vs. IPhone Retina Display Pixels

• The iPad's display features 132 pixels per inch. The iPhone 4's retina display features 326 pixels per inch, nearly 2.5 times more than the iPad. This increases what is called the "Resolution," and high resolution means more clarity, even at magnified levels. The iPad's screen is significantly larger than the iPhone's but the added resolution can make seeing images on the smaller screen as easy as viewing them at the iPad's larger size.
  
  

Additional Features

• The retina display also features higher contrast compared with the iPad's screen. This means that dark colors appear darker and whites appear whiter. This contrast, combined with the denseness of the pixels, is what makes the retina display screen easier to see in bright light. Bright surroundings, such as a sunny day, can reduce your eyes' ability to see the contrast on the screen, and glare from direct light on the glossy screen also causes visibility issues. The retina display does not eliminate glare issues entirely, but the higher contrast does improve visibility in bright light.
  
  

Similarities

• Despite the pixel differences and contrast, the iPad and the retina display on the iPhone 4 are both backlit LED glass screens. Both also use in-plane technology, or ITP, which is a method for creating screens that are visible at viewing angles up to 178 degrees, according to "PC World." This means you and your friends can share the screen on either device and receive clear viewing angles without squeezing together uncomfortably, unless there are quite a few of you.
  
  

Considerations

• Future generations of iPads may also use retina display screens, improving their resolution until it equals or surpasses the iPhone 4. With its larger screen size, a retina display on the iPad would offer an extremely high resolution viewing experience.