I love pies because of  they contains a filling of various sweet or savoury ingredients.
I do love pies but am not a baker so not sure what all goes in to making one. Would you happen to have any tips?
Yes, the crust matters alot. This is because Pies are defined by their crusts
I can see that. Are there different types of crust for different pies?
Before i answer you, let me give you a big clue, the filling is placed on top of the pastry but left open 
Well, I was asking because I thought I had heard before that there were different types of crust that could be used. Such as graham cracker crust, etc. Is that correct?
I'm not too sure but i know there is a top crust and a two crust pie  filling completely enclosed in the pastry shell.