IOS version history
Apple Inc. provides updates to the iOS operating system for the iPhone, iPad, and iPod Touch through iTunes and since iOS 5.0, over-the-air software updates. With the announcement of iOS 5.0 on June 6, 2011, a USB connection to iTunes was no longer needed to activate iOS devices; data synchronizing can happen automatically and wirelessly through Apple's iCloud service. The most recent stable update, iOS 10.2.1, was released on January 23, 2017, and the most recent beta update, iOS 10.3 Beta 2, was released on February 6, 2017.
Apple iOS did not have an official name until the release of the iPhone software development kit (iPhone SDK) on March 6, 2008. Before then, Apple marketing literature simply stated that their iPhone runs a version of OS X, a reference to iOS' parent operating system. When introduced, it was named iPhone OS. It was renamed iOS on June 7, 2010, as, with the introduction of the iPad, and the existence of the iPod Touch, the iPhone was no longer the only device to run the mobile operating system. iOS 4 was the first major release to reflect this change. Apple licensed the "iOS" trademark from Cisco Systems.
In June 2007, Apple released the first version of what became iOS – concurrently with the first iPhone. The final 1.x series release was 1.1.5, released shortly after version 2.0.
July 11, 2008, saw the public release of iPhone OS 2.0, with upgrades through version 2.2.1 made available.
June 17, 2009, was the release date for iPhone OS 3.0. For iPhones and iPod touches, iPhone OS 3 was updated through (and including) version 3.1.3 (released February 2, 2010). The first generation iPod Touch and iPhone have iPhone OS 3.1.3 as their newest available version. iOS 3.2.x was made specifically for the iPad.
On June 21, 2010, iOS 4.0 (formerly iPhone OS) was released to the public and was made available only to the iPod Touch and iPhone. iOS 4.0 was announced to have over 1500 new APIs for developers, with the highly anticipated multitasking feature. The iPod Touch (2nd generation) and iPhone 3G have iOS 4.2.1 as the final version available. Nevertheless, many features are not available for the iPhone 3G or iPod Touch (2nd generation), such as multitasking and home screen backgrounds. iOS 4.2 is the first version to bring major feature parity to the iPhone and iPad. The release of the CDMA iPhone for Verizon Wireless saw a branching of iOS. The 4.2 version sequence continued for the CDMA phone while 4.3 was released for all other products
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