Pictured is the T-Bone Steak & Porterhouse Steak. Both consist of the NY Strip on one side of the bone (the spine) and the Tenderloin, also known as Filet Mignon when cut, on the other side. The difference between the two is where the cut comes from. The Tenderloin is tapered, so cuts towards the head will result in a smaller portion of the Tenderloin on the steak (T-Bone), and cuts towards the tail will include larger portions of Tenderloin on the steak (Porterhouse).
When you’re filling out a cut sheet, this is why the option is T-Bones & Porterhouses OR NY Strips & Filets.