XAML simplifies C# code, especially when building a user interface.

Imagine that you need two or more buttons laid out horizontally to create a toolbar. In C#, you would write this code:

    var toolbar = new StackPanel(); 
    toolbar.Orientation = Orientation.Horizontal; 
    var newButton = new Button(); 
    newButton.Content = "New"; 
    newButton.Background = new SolidColorBrush(Colors.Pink); 
    toolbar.Children.Add(newButton); 
    var openButton = new Button(); 
    openButton.Content = "Open"; 
    openButton.Background = new SolidColorBrush(Colors.Pink); 
    toolbar.Children.Add(openButton); 

In XAML, this would be simplified to the following lines of code. When this XAML is processed, the equivalent properties are set, and methods are called to achieve the same goal as the preceding C# code:

    <StackPanel Name="toolbar" Orientation="Horizontal"> 
      <Button Name="newButton" Background="Pink">New</Button> 
      <Button Name="OpenButton" Background="Pink">Open</Button> 
    </StackPanel> 

XAML is an alternative (better) way of declaring and instantiating .NET types.

There are lots of predefined controls that you can choose from for common user interface scenarios. Almost all versions of XAML support these controls.