The iPhone ( /ˈaɪfoʊn/ EYE-fohn) is a line of smartphones designed and marketed by Apple Inc. It runs Apple's iOS mobile operating system, known as the "iPhone OS" until mid-2010, shortly after the release of the iPad. The first iPhone was released on June 29, 2007; the most recent iPhone, the sixth-generation iPhone 5, on September 21, 2012. The user interface is built around the device's multi-touch screen, including a virtual keyboard. The iPhone has Wi-Fi and cellular connectivity (2G, 3G and 4G).
An iPhone can shoot video (though this was not a standard feature until the iPhone 3GS), take photos, play music, send and receive email, browse the web, send texts, and receive visual voicemail. Other functions—games, reference, GPS navigation, social networking, etc.—can be enabled by downloading apps; as of 2012, the App Store offered more than 775,000 apps by Apple and third parties.
There are six generations of iPhone models, each accompanied by one of the six major releases of iOS. The original iPhone was a GSM phone, and established design precedents, such as screen size and button placement, that have persisted through all models. The iPhone 3G added 3G cellular network capabilities and A-GPS location. The iPhone 3GS added a faster processor and a higher-resolution camera that could record video at 480p. The iPhone 4 featured a higher-resolution 960 × 640 "retina display", a higher-resolution rear-facing camera and a lower-resolution front-facing camera for video calling and other apps. The iPhone 4S added an 8-megapixel camera with 1080p video recording, a dual-core processor, and a natural language voice control system called Siri. iPhone 5 features the new A6 processor, holds a 4-inch Retina display that is larger than its predecessor's 3.5-inch display, and replaces the 30-pin connector with an all-digital Lightning connector.
For some years, Apple and its manufacturing contractor Foxconn have received criticism due to poor working conditions at the assembly plant in China.