Final answer:
Joints are classified based on their mobility. Synarthrosis joints are immovable, amphiarthrosis joints are slightly moveable, and diarthrosis joints are freely moveable.
Step-by-step explanation:
The functional classification of joints is determined by the amount of mobility found between the adjacent bones. Joints are thus functionally classified as a synarthrosis or immobile joint, an amphiarthrosis or slightly moveable joint, or as a diarthrosis, which is a freely moveable joint.
Examples of synarthrosis joints include sutures in the skull, while amphiarthrosis joints include the pubic symphysis. Diarthrosis joints, which are freely moveable, include the shoulder and knee joints.