What protects bones and prevents them from wearing each other down?

Cartilage protects bones and prevents them from wearing each other down by covering the ends of bones where they meet at joints. This smooth, flexible tissue reduces friction during movement and acts as a shock absorber, allowing for easier motion and minimizing wear and tear. Synovial fluid, which lubricates the joints, further aids in this protective function. Together, these components ensure that bones can move smoothly against each other without damage.