Question Detail

1. Xamarin is a platform to create multi-OS apps
2. It allows you to create a single application, that can work across iOS, Android and Windows Phone.
3. In order to develop these applications, you use C# and XAML.
4. XAML acts as the markup and data binding language for the phone app, and C# acts as the server-side language.

If you want to use Xamarin to build Android apps then it is trivial. C# is almost identical to Java (with some added bonuses you don’t need to use at the start) and you can use all Android APIs, and Android UI language, so…. well, I can’t see anything that would stop you from doing that.
You can code specifically for iOS, Android or Windows phone. The alternative is to use Xamarin Forms which enables cross platform development. If you need something specific to the mobile device then you can use what’s called a custom renderer which will require knowledge of the underlying platform specifics.

Xmarine code is written in native C# while phone gap code is written in HTML CSS and JavaScript and when it comes to performance Xmarine code works just the same as an app written in native Java and X-Code for Ios.

The problem with PhoneGap is when you submit your App to PlayStore Google Developer Always tell you to Update your app to a later version that is when Adobe brings out a new update of their System.

Instead of PhoneGap use Iconic it's almost same as PhoneGap HTML CSS only that it mostly runs on angular JS that is Iconic FreamWork.