What are the three main types of joint in human body?

Fibrous joints: These joints are held together by fibrous connective tissue, such as ligaments. They allow for little or no movement, and are found in places like the skull and the joints between the teeth and the jaw.

Cartilaginous joints: These joints are held together by cartilage, a flexible, shock-absorbing tissue. They allow for more movement than fibrous joints, and are found in places like the joints between the vertebrae in the spine and the joints between the ribs and the sternum.

Synovial joints: These are the most common type of joint in the body. They are freely movable, and are composed of a joint capsule, a synovial membrane, and synovial fluid. The joint capsule is a tough, fibrous membrane that surrounds the joint and helps to hold it together. The synovial membrane is a thin, delicate membrane that lines the inside of the joint capsule and produces synovial fluid. Synovial fluid is a clear, viscous liquid that lubricates the joint and helps to reduce friction. Synovial joints are found in places like the knees, elbows, shoulders, and hips.