The display size and quality are important because smartphones can be controlled completely using their touchscreens. Larger screens are better for reading and web surfing, while larger displays can make it more difficult to transport. The screen's pixel density (measured in pixels per inch, ppi) will tell you how sharp and clear text will look on the screen. A smaller amount of pixels across large screens, such as a big one, can lead to jagged edges. The screen technology is also important. AMOLED and IPS are the main technologies. Each has its pros and cons.