awesome: I'm with "awesome" on this. I think of shade as a collection of shadows or as something used to get out of the sun. A shadow caused by a light or the moon is a little different. A shadow to me is primarily about the thing causing it. Also, a shadow is something that isn't normally thought for using as shade. When a shadow is used for shade it is often a temporary or unusual event. As using a tractor-trailer rig's shadow on the freeway to shade your vehicle or when someone happens to block the sun with their shadow giving you some shade.

awesome, Walter Montego: Thank you so much for your inputs. I was unsure about the use of the two words; in Czech there is only one expression for both of them. It's much clearer now.