Final answer:
The glenohumeral joint, known as the shoulder joint, is formed by the articulation between the glenoid cavity of the scapula and the head of the humerus, allowing for a large range of motion but also making it less stable.
Step-by-step explanation:
The glenohumeral joint, also known as the shoulder joint, is an articulation between two bones: the glenoid cavity of the scapula and the head of the humerus. It is a multiaxial ball-and-socket joint that allows for an extensive range of motion including flexion/extension, abduction/adduction, circumduction, and medial/lateral rotation of the humerus. Despite this mobility, the joint's stability is somewhat compromised owing to its loose articular capsule, though it is supported by ligaments and the rotator cuff muscles.