Loins being the long strip on the back (backstraps) and the tenderloins are the ones on the inside. If you go to a grocery store you can see the different cuts of pork. You will see the loins are much larger then the tenderloins.
Exactly. Loins and tenderloins. We call the larger loins backstrap, but they are technically loins. The little inside meats are tenderloins.
BTW - I've used 6 different butchers over the years and have never had one take the tenderloins or loins. They always ask how we want them, whole, chops or butterfly.