iOS (formerly iPhone OS) is a mobile operating system created and 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 and iPod Touch; the term also included the versions running on iPads until the name iPadOS was introduced with version 13 in 2019. 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.[10]

Commercial logo as used by Apple, since 2017
iOS 15 running on an iPhone 12 Pro
DeveloperApple Inc.
Written inC, C++, Objective-C, Swift, assembly language
OS familyUnix-like, based on Darwin (BSD), macOS
Working stateCurrent
Source modelClosed, with open-source components
Initial releaseJune 29, 2007; 14 years ago (2007-06-29)
Latest release15.0.2[1] (19A404)[2] (October 11, 2021; 13 days ago (2021-10-11)) [±]
Latest preview15.1 RC[3] (19B74)[4] (October 18, 2021; 6 days ago (2021-10-18)) [±]
Marketing targetSmartphones, tablet computers, portable media players
Available in40 languages[5][6][7][8]
Update methodOTA (since iOS 5), Finder (from macOS Catalina onwards)[9] or iTunes (Windows and macOS pre-Catalina)
Kernel typeHybrid (XNU)
user interface
Cocoa Touch (multi-touch, GUI)
LicenseProprietary software except for open-source components
Preceded byNewton OS
Support status
Articles in the series
iOS version history

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, Apple's App Store contains more than 2.1 million iOS applications, 1 million of which are native for iPads.[11] These mobile apps have collectively been downloaded more than 130 billion times.

Major versions of iOS are released annually. The current stable version, iOS 15, was released to the public on September 20, 2021.[12]