Border is a control that draws border, background or both around another control. It Is a container control such as Grid but you can declare only 1 child element inside it. You must add another container control like Grid or StackPanel to add more controls inside.
Border control looks like the following:

Blank Squire
Here's how we declare it inside XAML:
  1. <Border BorderBrush="Black" BorderThickness="1" Height="203" Width="343">
  2. //Container Controls or a child control can be declared here
  3. </Border>
Let's make another example on how to declare it.

Here's an example how to use single child control in a Border Control:
  1. <Border BorderBrush="Black" BorderThickness="1" HorizontalAlignment="Left" Height="203"
  2. Margin="136,103,0,0" VerticalAlignment="Top" Width="343">
  3. <CheckBox Content="Tick me!" />
  4. </Border>

Here's another example how to use StackPanel to contain many child controls inside a Border Control:
  1. <Border BorderBrush="Black" BorderThickness="1" HorizontalAlignment="Left" Height="203"
  2. Margin="136,103,0,0" VerticalAlignment="Top" Width="343">
  3. <StackPanel>
  4. <CheckBox Content="Tick Me"/>
  5. <CheckBox Content="Tick Me Too"/>
  6. <CheckBox Content="Tick Me Last"/>
  7. </StackPanel>
  8. </Border>

Border control is useful if you are going to contain or group controls inside a visually bordered control.