The Porterhouse and the T-bone come from the short loin portion of the cow. They are identified as similar cuts, being side by side on the short loin. Both are bone in N.Y. Strips, with a filet on the opposing side of the bone. The difference is that the Porterhouse has a much more significant amount of that Filet vs. the T-Bone. The Porterhouse will have a 6-8 oz Filet, and the T-Bone will have a 1-4 oz filet. Remember that bone is a good thing for holding in juices and adding flavor to the steak.