Wheel bearings are components that allow wheels to rotate freely while reducing friction and preventing excessive wear on the axle or hub. They consist of a bearing race, which is pressed into the wheel's center, and a metal ball that fits snugly inside the race. As the wheel rotates, the balls glide along the inner surface of the race, allowing for smooth rotation with minimal friction. Wheel bearings are essential to ensure proper steering and braking performance, as well as preventing damage to other components in the suspension system.