IOS



iOS is Apple's mobile operating system developed originally for the iPhone, and later deployed on the iPod Touch and iPad as well. It is derived from Mac OS X, with which it shares the Darwin foundation, and is therefore a Unix-like operating system by nature. In iOS, there are four abstraction layers: the Core OS layer, the Core Services layer, the Media layer, and the Cocoa Touch layer. The operating system uses roughly 500 megabytes of the device's storage.