Baby back ribs are a type of pork rib that come from the upper rib cage, beneath the loin muscle, and are curved where they meet the spine. They are called "babies" because they are shorter than spare ribs, ranging from around 3 to 6 inches in length. Depending on how they are butchered, they may have around half an inch of loin meat attached to the top. Baby back ribs are more tender and leaner than spare ribs, and are typically more expensive. Each rack of baby back ribs weighs around 2 pounds, around half of which is bone, and one rack feeds around one hungry adult.

In contrast, spare ribs are cut from the ends of baby back ribs and run along to the pigs breast bone. One side has exposed bone, where they meet the baby backs, and the other side, near the breast bone, is where the rib tips are, a flap of meat that has some small bones and cartilage in it. Spare ribs are flatter and contain more bone than meat but more fat, making them more tender than back ribs. They are typically more rectangular in shape than baby back ribs. Spare ribs take longer to cook than baby back ribs because of where the cut comes from and how large it is.

Both baby back ribs and spare ribs require low, slow cooking time to become tender, and they are great for smoking, braising, grilling, or can be cooked in the oven. They also take well to spice rubs and sauces. While baby back ribs and spare ribs have some differences, they are both delicious and can be substituted for each other depending on personal preference.