Your body is a collection of bones. When you were a baby you had 275 bones, but as you grow up 69 of them join together, so by the time you're an adult you will have just 206 separate bones.
All of the bones make up the skeleton. It's a kind of scaffolding which is inside you and hidden by muscles and skin.
Bones are not fixed together. Instead they are held together by muscles. This is why they can move.
