Answer:
Synovial joints or, more specifically, ball-and-socket joints
Step-by-step explanation:
On the left is the glenohumeral joint, also known as the shoulder joint, where the proximal end of the humerus bone (the head of the humerus) and the glenoid fossa of the scapula meet to form an articulation. On the right is the femoroacetabular joint, also known as the hip joint, where the proximal end of the femur (the head of the femur) and the acetabulum of pelvis meet to form an articulation.
Both of these joints are called synovial joints in which hyaline articular cartilage, a joint capsule, synovial fluid, a synovial cavity, and two or more bones, plus the addition of other potential structures come together to form some moving piece of the skeleton. More specifically, both of these joints are ball-and-socket joints, or spheroid joints, in which the spherical surface of one bone sits snugly within the cup-like surface of another bone and can articulate along more than just one plane comfortably.
These two specific joints are the only examples of ball-and-sockets in the human skeleton.