Wheel designs refer to the various shapes and structures of wheels used in vehicles and machinery. Common designs include the traditional circular wheel, which provides smooth movement, and specialized designs like the spoked wheel, which reduces weight while maintaining strength. Wheels can also vary in size, material, and tread patterns, affecting performance and durability. Different wheel designs serve specific purposes. For example, racing wheels are often lightweight and aerodynamic to enhance speed, while off-road wheels feature deeper treads for better traction on rough terrain. Innovations in wheel design continue to evolve, improving efficiency and safety in transportation.