Once the project is created from the selected template, you will see that the project has few files in it. Among them, you will find two XAML files (App.xaml and MainWindow.xaml) and two associated C# files (App.xaml.cs and MainWindow.xaml.cs) automatically created by Visual Studio:
The App.xaml file is the declarative start point of your application, which extends the Application class and subscribes to application-specific events, unhandled exception, and more. From this class, it gets the starting instruction to navigate to the initial window or page.
Here's the structure of the App.xaml file:
<Application ...
