Xamarin.Forms is a Cross-Platform Toolkit which helps share Business Logic as well as UI using XAML across all supported platforms.
It uses MVVM pattern along with Binding into the XAML UI to accomplish this. It produces pure native controls for each individual platforms. Using Xamarin.Forms, we can share the whole business logic as well as UI among all supporting platforms like iOS, Android and UWP. It also provides a way for platform specific customization of any native controls using Renderers. Thus, we can almost share about 80-90% of code across platforms. We can say Xamarin is the King of Cross Platforms
