Swift is a multi-paradigm, compiled programming language developed by Apple for iOS and OS X development. wikipedia.org

iOS (formerly iPhone OS) is Apple Inc.'s mobile operating system. Originally developed for the iPhone, it has since been extended to support other Apple, Inc. devices such as the iPod Touch, iPad, and Apple TV. wikipedia.org

Mobile application development is the process by which application software is developed for low-power handheld devices, such as personal digital assistants, enterprise digital assistants or mobile phones. wikipedia.org

The UIKit framework provides the classes needed to construct and manage an application's user interface for iOS. It provides an application object, event handling, drawing model, windows, views, and controls specifically designed for a touch screen interface.

Xcode is a suite of tools developed by Apple for developing software for Mac OS X and iOS, first released in 2003. wikipedia.org

The iPad is a line of tablet computers designed, developed and marketed by Apple Inc., primarily as a platform for audio-visual media including books, periodicals, movies, music, games, and web content. wikipedia.org

Mac OS is a series of graphical user interface-based operating systems developed by Apple Inc. for their Macintosh line of computer systems. wikipedia.org