Auto parts refer to components of a motor vehicle that are necessary for the proper functioning and operation of the vehicle. They are usually divided into two categories: service parts and replacement parts. Service parts are parts that require frequent maintenance and replacement such as spark plugs, air filters, and brakes. Replacement parts are parts that need to be replaced due to wear and tear such as tires, alternators, and radiators. Auto parts are typically made from various metals, plastics, and rubber. The metals used in auto parts include steel, aluminum, and iron. Steel is commonly used in the production of auto parts due to its strength and durability. Aluminum is also used in the production of auto parts, but it is more lightweight and corrosion-resistant than steel. Iron is also used in the production of auto parts, but it is less durable than steel and aluminum. Plastic is a common material used in the production of auto parts as it is lightweight and durable. It is used in the production of bumpers, grills, and various interior components. Rubber is also used in the production of auto parts, but it is more flexible than plastic. It is commonly used in the production of gaskets, hoses, and various seals.