How to idenitfy a type of apple tree?
 

Hi,

I moved into my current home about three years ago. There is a mature apple tree in the back garden which has, for the first time since we have been here, produced an abundance of fruit.

The problem is, I don't know what sort of apple it is! I am going to pick one and eat it, to get an idea of eating or cooking, but this does not seem very scientific to me.

Does anyone know a way of identifing the type of tree?