Stack Panel is one of the Silverlight panel elements enable layout. Stack panel arranges objects in a list, list can be vertical or horizontal depending upon the direction. Orientation property determined the direction of list, default value of orientation property is vertical.

Example

<StackPanel Margin="20">
    <Rectangle Fill="Brown"  Width="50" Height="50" Margin="5" />
    <Rectangle Fill="Blue" Width="50" Height="50" Margin="5" />
    <Rectangle Fill="Green" Width="50" Height="50" Margin="5" />
    <Rectangle Fill="Yellow"  Width="50" Height="50" Margin="5" />
</StackPanel>