Final answer:
The joint between the skull bones is referred to as sutures, which are immobile or essentially immobile joints.
Step-by-step explanation:
The joint between the skull bones are referred to as sutures. Sutures are a type of fibrous joint that strongly unites the adjacent skull bones, protecting the brain and forming the face. They are functionally classified as a synarthrosis, which means they are immobile or essentially immobile joints.