Cans are commonly used for metal packaging and come in different materials like steel and aluminum. Steel cans are often used for foods like soda, biscuits, tuna, beans, and corn to keep products safe. Aluminum cans are lighter weight and less expensive than steel, and have easy-open ends so a can opener isn't needed. However, cans can corrode if dropped and their solid shape makes them less flexible for storage than alternatives like paper bags.