The human skeleton consists of 206 bones that provide structure, allow for movement, and protect organs. Bones are made up of compact bone on the outside and spongy cancellous bone on the inside, with bone marrow in the center. Calcium is essential for strong bones and can be obtained through foods like dairy, broccoli, nuts and fortified juices. Joints connect bones and come in different forms like balls, hinges, and fixed joints. The skeleton differs between males and females, with males having thicker long bones and females having wider pelvises. Proper nutrition, exercise, hydration, and safety help keep the skeleton healthy.