Beef comes from cattle and is a good source of protein, iron, and vitamin B12. Cattle are considered finished between 18-22 months old when they weigh 1,100-1,250 pounds. They are then sent to packing plants where USDA inspectors examine each animal before processing to ensure food safety. Beef can be prepared in various ways like steak or ground beef and is graded based on factors like marbling and age. Grading provides an estimate of tenderness, juiciness, and flavor. Aging beef for 10-12 days enhances tenderness through natural enzymatic processes.