The type of joint between the human skull bones is called a fibrous joint.

Fibrous joints, also known as sutures, are found between the bones of the skull. These joints are characterized by the presence of fibrous connective tissue that holds the bones together. The fibrous tissue is composed of collagen fibers and lacks a joint cavity.

Structure of Fibrous Joints:
- Fibrous joints are formed by dense irregular connective tissue that allows for very little or no movement between the bones.
- The collagen fibers in the connective tissue are arranged in such a way that they provide strength and stability to the joint.
- The bones in fibrous joints are tightly bound together by the fibrous tissue, preventing any significant movement.

Function of Fibrous Joints in the Skull:
- The fibrous joints in the skull play a crucial role in protecting the brain and providing stability to the skull.
- These joints allow for minimal movement, primarily during childbirth or growth of the skull in infants.
- The immobility of these joints prevents displacement or misalignment of the bones, ensuring the structural integrity of the skull.

Types of Fibrous Joints in the Skull:
- The skull primarily consists of two types of fibrous joints: sutures and fontanelles.
- Sutures are immovable joints found between the flat bones of the skull, such as the parietal and frontal bones.
- Fontanelles, also known as soft spots, are areas of fibrous connective tissue found in the skulls of infants. These allow for slight movement and growth of the skull during early development.

Conclusion:
In conclusion, the type of joint between the human skull bones is a fibrous joint. These joints are formed by fibrous connective tissue and provide stability to the skull. The immovable nature of these joints ensures the protection and integrity of the brain.