Articular cartilage is a firm rubbery tissue that covers the ends of bones. It provides a smooth gliding surface between joints and acts as a cushion between bones. Cartilage can break down due to overuse or injury, which can lead to pain and swelling and problems with your joint.
Further, surgeons typically perform this procedure on a person who has a specific cartilage defect, usually caused by an injury. It is not done when cartilage loss is much more extensive.
The video below will give you a general overview of the procedure. Your own surgery will be determined by the conditions of the cartilage defect and the judgement of your surgeon.