Explanation

Your skull is the hard thing you feel when you touch your head! Its job is to provide proper protection for your brain. Your skull is actually not one single bone but 22! One, your jaw, can move, but the other 21 are fused together by fibrous joints.

Your brain sits inside your skull, so if you hit your head, or dive into water, your brain is unlikely get hurt. Between your skull and your brain is a protective layer called the meninges.