On a human, we have shoulders, upper back, middle back, lower back and ass. On a cow, these are called Chuck, Rib, Top Loin, Loin and Round. Both critters have muscles that run parallel to the spine. Ribeyes come from the rib primal, and are more tender and have a richer more buttery flavor. Go assward past the top loin primal where T-bones come from and you arrive at the Loin primal where we get among other things sirloin steaks, which compared to ribeyes are chewier but bring a more meaty, beefy flavor.