Wheel spokes are the rods that connect the center of a wheel to its outer edge. They are typically made of metal and are arranged in a radial pattern, with each spoke radiating out from the center. The term 'RADII' refers to the lines that connect the center of the wheel to the outer edge, while 'RUNGS' refer to the individual spokes themselves. Together, these components form the structure of a wheel, allowing it to rotate and support the weight of whatever is attached to it.