Combined tech refers to joining two or more materials to make one product. Examples given include cars, boats, humans/animals, and planes. Planes have GPS features and engines in their wings to allow pilots to navigate and power flight. Humans and animals are combined tech internally, with parts like the heart, spine and skin interacting to enable movement, breathing and speech. Boats similarly have internal components like engines that work together to steer and maneuver the craft. Cars also represent combined tech, requiring someone to steer and an engine to power movement, with constant improvements made to meet different needs.