The iPhone 4 is a touchscreen 3G smartphone. It is the fourth generation iPhone, and successor to the iPhone 3GS. It has features like video calling , consumption of media such as books and periodicals, movies, music, and games, and for general web and e-mail access. The iPhone 4 runs Apple's iOS operating system, the same operating system as used on prior iPhones, the iPad, and the iPod Touch. It is mainly controlled by a user's fingertips on the multi-touch display, which is sensitive to fingertip contact.