Overview

Prefer x:Bind over Binding whenever possible.

Binding

<TextBlock Text={"Binding Path=…}"/>

Resolves binding path at runtime

Data Sources

ElementName, Source, or RelativeSource
Uses DataContext if none of the above are set

x:Bind

<TextBlock Text={"x:Bind Path=…}"/>

Resolves binding path a compile time
Creates C# code behind the scenes

Data Sources

Does not use data sources.
Uses Root object of XAML document (an instance of the class that is specified with the x:Class attribute)

Advantages of x:Bind

Better performance
Compile-time errors
Better debugging experience (ability to step into genereated data binding code)

Example with x:Bind

MainWindow.xaml.cs

public sealed partial class MainWindow : Window
{
    public MainViewModel ViewMode { get; }

    public MainWindow()
    {
        this.InitializeComponent();

        Title = "Customers App";
        // Set the ViewModel property to the MainViewModel:
        ViewModel = new MainViewModel(new CustomerDataProvider());
        // Not needed when using x:Bind:
        // root.DataContext = ViewModel;
        root.Loaded += Root_Loaded;
    }
}

MainWindow.xaml

<!-- Change from Binding to x:Bind: -->
<ListView Grid.Row="1" x:Name="customerListView"
    ItemsSource="{x:Bind ViewModel.Customers,Mode=OneWay}"
    SelectedItem="{x:Bind ViewModel.SelectedCustomer,Mode=TwoWay}"
    DisplayMemberPath="FirstName"
    ScrollViewer.HorizontalScrollMode="Enabled"
    ScrollViewer.HorizontalScrollBarVisibility="Auto"/>

    <!-- Customer detail --->
    <StackPanel Grid.Row="1" Grid.Column="1" Margin="10">
        <TextBox Header="Firstname" 
            Text="{x:Bind ViewModel.SelectedCustomer.FirstName, Mode=TwoWay UpdateSourceTrigger=PropertyChanged}"/>
        <TextBox Header="Lastname"
            Text="{x:Bind ViewModel.SelectedCustomer.LastName, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}",
            Margin="0 10 0 0"/>
        <CheckBox Margin="0 20 0 0"
            IsChecked="{x:Bind ViewModel.SelectedCustomer.IsDeveloper, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}">
            Is developer
        </CheckBox>
    </StackPanel>