Making the Grade.
Beef is almost always labeled by its grade: Prime, Choice, or Select; but what does it really mean?  Here is a quick guide to help you know what you are buying.  Each USDA beef quality grade is a measure of a distinct level of quality.  The grade is determined by the amount of marbling and the age of the animal.  Marbling is the flecks of fat that are distributed throughout the lean meat.  The higher the grade, the more likely you will have a tender, juicy and flavorful eating experience.  Here are the top three grades available in a grocery store.

USDA Prime:  Prime grade beef is the ultimate in tenderness, juiciness, and flavor.  It has lots of marbling which enhances both flavor and juiciness.  It is generally sold to finer restaurants and is available in a select few retail markets.  It is usually higher priced because it is available in very limited quantities.

USDA Choice:  Choice grade beef has less marbling than Prime but will still be tender, juicy, and flavorful.  This is the grade available in most retail markets and provides a great eating experience and is usually less costly than USDA Prime.

USDA Select:  Select grade beef is fairly tender, but, because it has less marbling, it may lack some of the juiciness and flavor of the higher grades. 

Courtesy of The Beef Council