The OP writes: *Or am I too serious on this and are these two terms very much interchangeable? Yes, you are :D As an American, it really doesn’t matter, although the distinction Sam makes is accurate. In fact, we’ll often say “the pantry”, even though most houses don’t have a real “pantry” these days. In real life, it's not clear when we would even need to use these words (other than when purchasing cupboards / cabinets). If a guest wants something from the kitchen, I’ll go get it for them, or if they really insist on self-service, they don’t need me to tell them the potato chips are in the cabinet as opposed to the refrigerator. Or do they…?

Growing up we always said cupboard (maybe British) but these days I also hear cabinet more. (Canada) Possibly an evolution.

From the American point of view, I think that cabinet and cupboard are pretty much interchangeable. A free-standing piece of furniture that is intended to hold dishes would be called a hutch.

Interesting! I can only speak for UK English but I think there is a difference. "Kitchen cabinets" is usually used for the built in cupboards that you get in kitchens, what we call a fitted kitchen. I would say that it is used to talk about the all the storage that you have in the kitchen, i.e. often in the plural. I would ask someone, "which cupboard do you keep the glasses in" but I would say, "your kitchen cabinets are really nice". The word cabinet (separately from kitchen cabinet) tends to refer to a more sophisticated object (e.g. a drinks cabinet) and a cabinet must always have shelves, whereas a cupboard could have shelves but might just be a large space with door.