All the bones in the human body together are called the skeletal system. The skeletal system provides strength and rigidity to our body so we don't just flop around like jellyfish. We have 206 bones in our body. Each bone has a function. Some bones offer protection to softer more fragile parts of our body. For example, the skull protects the brain and the rib cage protects our heart and lungs. Other bones, like bones in our legs and arms, help us to move around by providing support for our muscles.

The skeletal system includes more than just bones. It also includes tendons, ligaments, and cartilage. Tendons attach our bones to muscles so we can move around. Ligaments attach bones to other bones.

Source: https://www.ducksters.com/science/bones.php