The development of the iPhone completely redefined the possibilities of the telephone. Since then the design has constantly evolved and improved. The iPhone 4 is extremely thin – only 9.3 mm in thickness – and is very pleasant to hold. The front and back are protected by two high-gloss aluminosilicate glass plates, a material that is used for the windscreens of high-speed trains. It is chemically hardened which makes it 30 times harder than plastic. All of the components of the iPhone 4 are protected by a supporting frame made of very hard, CNC milled stainless steel. The nature of this material means that the phone is extremely robust, scratch-resistant and durable. The ground-breaking new design of the body of this new smartphone together with an innovative multi-touch display offers the user a fascinating surface for new applications. The new Retina display of the iPhone 4, with its resolution of 960 x 640, is so sharp that the human eye can no longer detect the individual pixel. On this display, users can experience iPhone 4’s new possibilities such as FaceTime, which makes video calling a reality, and equally intensively, intelligent multitasking which enables them to activate various apps at the same time and to switch trouble free from one to another.