A wearable computer is a computer that is worn on the body, usually in the form of a garment. The most common type of wearable computer is the wristwatch, which has been used for centuries. However, there are many other types of wearable computers, including those that are worn on the head, on the body, or even on the feet.What are some examples of wearable computers? How do they work? What are their advantages and disadvantages?