The iPhone 4 is a touchscreen 3G smartphone developed by Apple Inc. It is the fourth generation iPhone, and successor to theiPhone 3GS. It is particularly marketed for video calling (marketed by Apple as FaceTime), consumption of media such as books and periodicals, movies, music, and games, and for general web and email access. It was announced on June 7, 2010, at the Apple Worldwide Developers Conference (WWDC) 2010, held at the Moscone Center, San Francisco,[8] and was released on June 24, 2010, in the United States, the United Kingdom, France, Germany and Japan.
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. It originally shipped with iOS 4. The latest version available is iOS 7 (September 18, 2013).[9]
The most noticeable difference between the iPhone 4 and its predecessors is the new design, which incorporates an uninsulated stainless steel frame that acts as the device's antenna. The internal components of the device are situated between two panels of chemically strengthened aluminosilicate glass.[10] It has an Apple A4 processor and 512 MB of DRAM, twice that of its predecessor and four times that of the original iPhone. Its 3.5-inch (89 mm) LED backlit liquid crystal display with a 960×640 pixel resolution is marketed as the "Retina display".
In October 2011, the iPhone 4S was announced, which retains the same form factor but includes upgrades such as the A5 processor,Siri, and an improved camera.[11]
On September 10, 2013, Apple discontinued the iPhone 4 in the United States with the introduction of the iPhone 5C and the iPhone 5S.[12] Its role as the entry level free smartphone was replaced by the iPhone 4S. However, it is still avaliable in China for RMB 2,588 (approximatley 422.77 US dollars) [13]
