Why are there sutures on the human skull? what does this tell you about the actual structure of the skull?

These sutures are actually small divisions between the bones of the skull which are used during the early stages of the human's life to give space and allow the growth of the brain and the skull. After the skull and brain are fully developed, these sutures fuse together.

These sutures helped us understand that the skull is not made of a single large bone, but rather of a number of small bones.

More; less is the correct answer