The iPhone is a smartphone made by Apple that combines a computer, iPod, digital camera and cellular phone into one device with a touchscreen interface. The iPhone runs the iOS operating system (OS), and as of 2017, there were 2.2 million apps available for it through the Apple App Store, according to Statista.
Apple regularly releases new iPhone models, introducing new features and design changes.
As of 2017, the newest version was the iPhone X (pronounced iPhone 10), which eliminated the traditional Home button in favor of a fully touchscreen interface.
The first-generation iPhone was extremely thin (only 11.6 mm thick) but wider and longer than many comparable devices. The display area was a 3.5 inch-wide screen with a multitouch interface and unusually high resolution (160 pixels per inch). Unlike most other smartphones at the time, iPhone did not use a hardware keyboard or a stylus. Instead, a user relied on multiple taps and drags to navigate through iPhone OS 1.0, a mobile version of Apple's OS X for Mac computers. Like the iPod, the iPhone synchronized data with a user's personal computer via a USB port, using Apple iTunes as client software.
iPhone 3G, 3GS
Apple released the second-generation iPhone and iPhone OS 2.0 on July 11, 2008. The new device was called the iPhone 3G, a nod to its new ability to connect to third-generation (3G) cellular networks powered by technologies such as UMTS (Universal Mobile Telecommunications Service) and HSDPA (High-Speed Downlink Packet Access). It was available in 8 GB and 16 GB models.
The iPhone OS 2.0 update included a number of features designed for business, including support for Microsoft Exchange email. Improved mobile security features included secure access to corporate networks over Cisco's IPSec virtual private network (VPN), plus remote wipe and other management capabilities.
iPhone 4 and 4S
Apple released the iPhone 4 on June 21, 2010. With this model, Apple also changed the name of the OS from iPhone OS to iOS. The name change was made in the aftermath of the April 3, 2010, release of the iPad, which ran the same OS.
iPhone 5, 5C and 5S
The Apple iPhone 5, which was released on Sept. 21, 2012, featured a taller screen than its predecessors, measuring 4 inches diagonally with a 16:9 widescreen aspect ratio and 1136 x 640 resolution. It ran on Apple's A6 processor and included a specially designed nano-SIM card, plus a new connector that was not compatible with plugs and accessories for the iPad, iPod or previous iPhones. The iPhone 5 was also the first iPhone to support LTE (Long-Term Evolution) networks and the 5 GHz wireless band. It was available in 16 GB, 32 GB and 64 GB models.
iPhone 6 and 6 Plus; 6S and 6S Plus
Apple released the iPhone 6 and 6 Plus on Sept. 19, 2014. It marked the first time that one iPhone model was available in two different sizes. The iPhone 6 featured a 4.7-inch display with a 1334 x 750 resolution, and the iPhone 6 Plus had a 5.5-inch display with a 1920 x 1080 resolution. Both devices ran Apple's A8 processor and M8 motion coprocessor, and they were the first to come with Apple Pay, Apple's mobile payments service.
Apple released the iPhone SE, a smaller version of the iPhone 6S, on March 31, 2016.
The iPhone SE featured a 4-inch display but ran on the same A9 and M9 chips as the iPhone 6S and 6S Plus. It was available in 16 GB and 64 GB models and came in four colors: space gray, silver, gold and rose gold.
iPhone 7 and 7 Plus
The iPhone 7 and 7 Plus, released on Sept. 16, 2016, boasted Apple's first water- and dust-resistant casing. The devices, which came in 32 GB, 128 GB and 256 GB versions, also featured two 12-megapixel cameras and Apple's new four-core A10 Fusion processor.
In a major design change, Apple eliminated the headphone jack in the iPhone 7 and 7 Plus, forcing users to either rely on wireless headphones or an adapter for the iPhone's Lightning port.
The iPhone 7 and 7 Plus shipped with iOS 10, whose new features included Siri integration with third-party apps and expanded 3D Touch capabilities.
iPhone 8 and 8 Plus
Apple gave the iPhone 8 and 8 Plus a new aluminum-and-glass design, a six-core A11 Bionic processor and wireless charging capabilities. The devices, released on Sept. 22, 2017, also had new cameras built especially for augmented reality (AR) use cases. Both models came in two sizes: 64 GB and 256 GB.
The iPhone 8 and 8 Plus shipped with iOS 11, which included ARKit, an SDK for AR apps.
Apple also released the iPhone X at the same time as the iPhone 8 and 8 Plus. The iPhone X eliminated the physical Home button that was present on every preceding iPhone model, giving the device a touchscreen-only interface.
The iPhone X featured an all-glass design and 5.8-inch display, making it the largest iPhone in history. The device also marked the debut of Face ID, a new way of authenticating user access through facial recognition technology.