apple iphoneiPhone(/afon/eye-fohn) is a line ofsmartphonesdesigned and marketed byApple Inc.It runs Apple'siOSmobile operating system.[13]Thefirst generation iPhonewas released on June 29, 2007; the most recent iPhone models are theiPhone 6 and iPhone 6 Plus, which were unveiled at a special event on September 9, 2014.[14]Theuser interfaceis built around the device'smulti-touchscreen, including avirtual keyboard. The iPhone hasWi-Fiand can connect to many cellular networks, including1xRTT(represented by a 1x on the status bar) andGPRS(shown as GPRS on the status bar),EDGE(shown as a capital E on the status bar),UMTSandEV-DO(shown as 3G), a faster version of UMTS and 4G (shown as a 4G symbol on the status bar), andLTE(shown as LTE on the status bar).[15]An iPhone canshoot video(though this was not a standard feature until theiPhone 3GS),take photos,play music, send and receive email,browse the web, sendtexts,GPS navigation, record notes, do mathematical calculations, and receivevisual voicemail.[16]Other functionsvideo games, reference works, social networking, etc.can be enabled by downloadingapplication programs (apps); as of October 2013, theApp Storeoffered more than one million apps by Apple and third parties[17]and is ranked as the world's second largest mobile software distribution network of its kind (by number of currently available applications).[18]There are eightgenerationsof iPhone models, each accompanied by one of the eight major releases ofiOS. The original1st-generation iPhonewas aGSMphone and established design precedents, such as a button placement that has persisted throughout all releases and a screen size maintained for the next four iterations. TheiPhone 3Gadded3Gcellular network capabilities andA-GPSlocation. TheiPhone 3GSadded a fasterprocessorand a higher-resolution camera that could record video at480p. TheiPhone 4featured a higher-resolution 960640 "Retina Display", a VGA front-facing camera for video calling and other apps, and a 5-megapixel rear-facing camera with 720p video capture.[19]TheiPhone 4Supgrades to an 8-megapixelcamera with1080pvideo recording, a dual-core A5 processor, and anatural languagevoice controlsystem calledSiri.[20]iPhone 5features the dual-coreA6processor, increases the size of the Retina display to 4 inches, introducesLTEsupport and replaces the 30-pin connector with an all-digitalLightning connector. TheiPhone 5Sfeatures the dual-core64-bitA7processor, an updated camera with a largerapertureand dual-LED flash, and theTouch IDfingerprint scanner, integrated into the home button. TheiPhone 5Cfeatures the sameA6chip as theiPhone 5, along with a new backside-illuminatedFaceTimecamera and a new casing made ofpolycarbonate. TheiPhone 6andiPhone 6 Plusfurther increased screen size, measuring at 4.7 inches and 5.5 inches, respectively. In addition, they also feature a newA8chip andM8motion coprocessor. As of 2013, the iPhone 3GS had the longest production run, 1,181 days; followed by the iPhone 4, produced for 1,174 days.[21]The resounding sales of the iPhone, at the time, have been credited with reshaping the smartphone industry and helping make Apple one of the world's most valuable publicly traded companies in 201112.[22]In late 2014, JP Morgan estimated "iPhone percentage of the worldwide smartphone install base has been around 15% since late 2012"[23]being far behind the dominantAndroid-based smartphones. In a few mature markets countries such as; Japan, the iPhone has a majority, an exception to Android's dominance,[24]and Australia where Android is rapidly approaching parity. In March 2014, sales of the iPhone brand had reached 500 million devices.[25]In the last quarter of 2014, there were 74.5 million iPhones sold, a new record, compared to 51.0 million in the last quarter of 2013.[26]Tim Cook revealed at theApple Watchconference on March 9, 2015 that Apple had sold a total of 700 million iPhones to date.[1]