What exactly is a lumbar disc in your back?

Low back area: These are the lower back discs in the small of your back.

It is a structure: That acts like a joint by joining 2 bones together while allowing motion and weight bearing. It is 90% water at birth and dries up as we age. It has 2 distinct parts, an outer or annulus layer and an inner core, the jelly like nucleus pulposus. The annulus is similar to steel belts in a tire wrapping around forming the outer layer as a strong, tough layer that frays and cracks with age.