Steak is sliced meat that comes from the fleshy part of cows - usually across muscle fiber and sometimes with the bone still ...

Sirloin comes from the top of the cow's back ... but anything thinner is considered a T-bone steak. T-bone and porterhouse also come from slightly different portions of the cow.

The porterhouse is that beautiful cut of meat with a large, T-shaped bone in the middle—the larger side represents the strip loin and the smaller side is a portion from the tenderloin.