Attached Properties help !!

Question

I am beginner in WPF and use this book http://apress.com/book/view/1430272058
I came to the champter 2 and threre is Attached Properties explanation but I couldn't understand very well there is this example:

 
<Grid> 

 <TextBox Height="23" HorizontalAlignment="Left" Margin="104,103,0,0" Name="textBox1" VerticalAlignment="Top" Width="120" Grid.Row="0"/>

  <TextBox Height="23" HorizontalAlignment="Left" Margin="104,189,0,0" Name="textBox2" VerticalAlignment="Top" Width="120" Grid.Row="1"/> 

</Grid>





  

as you can see threre are 2 attached properties Grid.row="0" and Grid.row="1" what does it means, Grid or Button is not affected in disaigner or when i run code