In-cell technology, used by Apple, has electrodes placed on a layer of glass underneath the LCD panel. Employed by the Cupertino based tech titan ever since it released the Apple iPhone 5, use of an in-cell touchscreen is one reason why Apple has been able to make its recent full-featured models so thin. The Apple iPhone 5s is just 7.6mm thin.
Meanwhile, LCD screens that use on-cell technology can achieve a pixel density of only 200ppi. The glass used for these screens has the electrodes deposited on the outer layer of protective glass. These displays are expected to be used in 2014, on low to mid-range models produced by Chinese manufacturers.