The full form of iOS is "iPhone Operating System". It is a proprietary mobile operating system developed and distributed by Apple Inc. that runs on Apple devices like the iPhone, iPad, and iPod. The first version of iOS was released on July 29, 2007. The iOS developer kit provides tools that allow for iOS app development. The mobile OS supports input through direct manipulation and responds to various user gestures, such as pinching, tapping, and swiping. As of 2023, the Apple iOS market share was 19.9% worldwide, according to IDC.