A prosthesis is an artificial body part that can be attached to your body. It can be used to replace a missing body part or to make existing body parts stronger. For example, people who have lost a leg can get a prosthetic leg, which is an artificial one that looks and works like a real one. People who are missing an arm can get a prosthetic arm, and people who are unable to use their legs can get a wheelchair that makes it easier to move around. Prostheses can also be used to help people who have lost sensation in their hands or feet.