Question - How Xamarin.Android applications work?
Answer -
Xamarin.Android applications depend on Microsoft's Mono Virtual Machine. Mono is Microsoft's open-source implementation of the .Net Framework, which is based on open source standards of C# and CLR. Mono was launched in the year 2001. It was created to allow the .Net applications to work on the Linux platform, but was later modified to support the development on various devices, including embedded systems.
In Xamarin, Mono works in parallel with Android's ART. On Android, most of the system facilities like Audio, Graphics, OpenGL, and Telephony are not available directly to the native applications. They can be added through the Android Runtime Java APIs, which is available in one of the Java.*namespaces or the Android.*namespaces. The native applications then interact with the exposed .NET APIs. These APIs then, through the Android Binding, call the Android runtime Java APIs.
The architecture looks like this: