The 3-2-1 is a reticle that is thick on the outside edge (hence 3), then thinner as you go towards the middle of the scope (hence 2) and then thin as you go more towards the middle of the scope (hence 1), and then I think is is the very thin X.
The fast focus is simply a knob on the side of the scope (I'm pretty sure) and you can adjust the focus quicker than if it was, as is standard, on the rear tube of the scope.
Zachary