A subframe is a secondary structure that supports the main frame of a vehicle or machinery. It is often used to hold components like the engine, suspension, or transmission, providing additional stability and strength. By distributing loads more evenly, a subframe helps improve the overall performance and safety of the vehicle. In automotive design, subframes can be made from various materials, including steel and aluminum, to balance weight and durability. They are commonly found in cars, trucks, and motorcycles, playing a crucial role in the vehicle's handling and ride quality.