Typically used in an office whether home or commercial for its unmatched file storage abilities. Standard as 54" wide with three drawer bays (two file/ one misc drawer per bay).
Are the options confusing? Just take the default if in doubt. The default choices are proven to be satisfying.
Keep in mind that pullouts less deep are less usable.
Specifying which of the pullouts are for files is tricky, because just any size pullout cannot be a file pullout. We need to talk about your big picture needs to plan for files.
As the height increases, the file drawers aty the same but the top pullouts increase in size.
What is a Credenza? A Case which holds useful things, working things, maybe pleasurable working things. But something we use, not just for meals or entertainment. Usually it has a combination of drawers and drawers, but not always. So a Credenza is only vaguely defined. If you tell me you want a Credenza and it looks more like a Buffet to me I'm not going to miss a beat. We'll call it a Credenza.