Poultry
The USDA grades for poultry are A, B, and C.

• Grade A is the highest quality and the only grade that is likely to be seen at the retail level. This grade indicates that the poultry products are virtually free from defects such as bruises, discolorations, and feathers. Bone-in products have no broken bones. For whole birds and parts with the skin on, there are no tears in the skin or exposed flesh that could dry out during cooking, and there is a good covering of fat under the skin. Also, whole birds and parts will be fully fleshed and meaty.
  The grade shield for poultry may be found on the following chilled or frozen ready-to-cook poultry products: whole carcasses and parts, as well as roasts, tenderloins, and other boneless and/or skinless poultry products that are being marketed. There are no grade standards for necks, wing tips, tails, giblets, or ground poultry.
• Grades B and C poultry are usually used in further-processed products where the poultry meat is cut up, chopped, or ground. If sold at retail, they are usually not grade identified.

Beef
USDA Grades for Meat and Poultry

• Quality grades - for tenderness, juiciness, and flavor; and
• Yield grades - for the amount of usable lean meat on the carcass. There are eight quality grades for beef. Quality grades are based on the amount of marbling (flecks of fat within the lean), color, and maturity.

• Prime Grade is produced from young, well-fed beef cattle. It has abundant marbling and is generally sold in restaurants and hotels. Prime roasts and steaks are excellent for dry-heat cooking (i.e., roasting, broiling, and grilling).
• Choice Grade is high quality, but has less marbling than Prime. Choice roasts and steaks from the loin and rib will be very tender, juicy, and flavorful and are, like Prime, suited to dry-heat cooking. Many of the less tender cuts, such as those from the rump, round, and blade chuck, can also be cooked with dry heat, but be careful not to overcook them. Using a meat thermometer takes the guesswork out of cooking and assures a safe internal temperature: 145 °F is medium rare; 160 ° F, medium; and 170 °F, well done.
• Select Grade is very uniform in quality and normally leaner than the higher grades. It is fairly tender, but, because it has less marbling, it may lack some of the juiciness and flavor of the higher grades. Only the tender cuts (loin, rib, sirloin) should be cooked with dry heat. Other cuts should be marinated before cooking or cooked with moisture to obtain maximum tenderness and flavor.
• Standard and Commercial Grades frequently are sold as ungraded or as "store brand" meat.
• Utility, Cutter, and Canner Grades are seldom, if ever, sold at retail but are used instead to make ground beef and processed products.