Scrap metals include a variety of metal materials that have lost their usefulness in their original state. These can range from household items like aluminum cans to industrial components such as copper wiring. Scrap metals can be classified into different types, including ferrous metals such as iron and steel, which are magnetic, and non-ferrous metals like aluminum, copper, lead, zinc, and precious metals. Each category of scrap metal has unique properties and market values, making proper classification essential for recycling and resale purposes.