iOS app development is the process of creating mobile applications for the Apple iPhone. iOS and Google’s Android operating system power nearly all of the smartphones in the world today; however, unlike Android phones produced by a vast ecosystem of manufacturers at a variety of price points, iOS only runs on relatively expensive, Apple-produced iPhones. But because of their excellent performance and build quality, clean user interface, and family of apps that work together seamlessly, the iPhone is the most popular smartphone in America, making learning iOS programming very important for mobile app developers.
For much of its history, iOS app development relied upon Objective-C, an object-oriented programming language built on the C programming language. In 2014 however, Apple introduced Swift, a faster and more concise programming language used across iOS as well as macOS. Swift remains the main programming language for iOS, and is often used in conjunction with the Core Data framework for data functionality and other tools built into the Xcode integrated development environment (IDE).