The "body-on-frame" design is a vehicle construction method where the body of the vehicle is mounted on a separate frame. This frame, typically made of steel, provides structural support and rigidity, allowing for better handling and durability. This design is commonly found in larger vehicles like trucks and SUVs, where strength and towing capacity are important. In contrast to unibody construction, where the body and frame are integrated, body-on-frame vehicles can be easier to repair and modify. This design allows for greater flexibility in terms of vehicle size and configuration, making it popular among manufacturers like Ford and Chevrolet.