I believe it is both. Short prints are considered more rare and tougher to pull than "regular" base cards. The code on the back is also different, which is one of the easiest ways to tell if you have a short print vs regular base card (depending on your eyesight, I suppose).
I hope that answers your question, but if not perhaps others will chime in and provide a better answer than I did.
I'll never quit collecting entirely, but I am downsizing. Check out my COMC store and help me thin out what I don't want so I can buy cards that I do want. See something you like? Send me a message on here, and we can knock the price down quite a bit. I'll even take a bit of a loss if it means getting you a card you really want.