"Prime" has the most fat marbling (flavor); "Choice" is leaner but more common and affordable.
đź’ˇ If the label doesn't say "USDA Prime," it's technically just a rib roast, not "Prime" rib. If you'd like to get cooking, I can help with: buying prime rib at the grocery store
This comes from the back of the rib (ribs 10-12); it’s leaner and has one large "eye" muscle. "Prime" has the most fat marbling (flavor); "Choice"
(like the reverse sear method) Internal temperature guides (for perfect medium-rare) buying prime rib at the grocery store