Let's start by getting the basics out of the way: React Native is a framework for creating multi-platform apps (for iOS, Android, smart TVs, web etc) based on the JavaScript and React. It is (mainly) maintained by Facebook.

Why React though?#

React is a framework that was created due to the need to keep JavaScript SPAs (single page applications) performant. It works by declaring UI elements as functions. By doing this the user interface becomes declarative; given the same inputs, it should produce the same outputs.

Although originally it was not the main focus, React put the spotlight onto breaking your UI into chunks, or components, and this abstraction works really well to divide your UI into manageable sized pieces of code.

Microsoft joins the fight#

Last year, Microsoft decided to jump into the ring and add support for both Windows and macOS. The macOS port uses either Objective-C or Swift for the native code, and the Windows version uses C#. We will use Swift to interact with the native APIs of macOS, and some of the knowledge should be transferable to Windows if you can program in C#.