|Written in||C, C++, Objective-C, Swift, assembly language|
|OS family||Unix-like, based on Darwin (BSD), macOS|
|Source model||Closed, with open-source components|
|Initial release||June 29, 2007|
|Latest release||16.3 (20D47) (January 23, 2023 )|
|Marketing target||Smartphones, tablet computers, portable media players|
|Available in||40 languages|
|Update method||OTA (since iOS 5), Finder (from macOS Catalina onwards) or iTunes (Windows and macOS pre-Catalina)|
|Kernel type||Hybrid (XNU)|
|Cocoa Touch (multi-touch, GUI)|
|License||Proprietary software except for open-source components|
|Preceded by||Newton OS|
|Articles in the series|
|iOS version history|
iOS (formerly iPhone OS) is a mobile operating system developed by Apple Inc. exclusively for its hardware. It is the operating system that powers many of the company's mobile devices, including the iPhone; the term also includes the system software for iPads predating iPadOS—which was introduced in 2019—as well as on the iPod Touch devices—which were discontinued in mid-2022. It is the world's second-most widely installed mobile operating system, after Android. It is the basis for three other operating systems made by Apple: iPadOS, tvOS, and watchOS. It is proprietary software, although some parts of it are open source under the Apple Public Source License and other licenses.
Unveiled in 2007 for the first-generation iPhone, iOS has since been extended to support other Apple devices such as the iPod Touch (September 2007) and the iPad (introduced: January 2010; availability: April 2010.) As of March 2018[update], Apple's App Store contains more than 2.1 million iOS applications, 1 million of which are native for iPads. These mobile apps have collectively been downloaded more than 130 billion times.