How to do Xamarin.Android applications work?

Xamarin.Android applications depend on Microsoft's Mono Virtual Machine. Mono is Microsoft's open-source implementation of the .Net Framework based on open standards for C# and CLR. Launched in the year 2001, it was mainly created to allow .Net applications to work on Linux platform, but was later modified to support 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 native applications, they are only exposed through the Android Runtime Java APIs residing in one of the Java.* namespaces or the Android.* namespaces. The native applications interact with the exposed .NET APIs. These APIs then, through Android Binding call the underlying Android Runtime Java APIs.