Which word is different from the others: planet, remote control, coat, elevator?

The word "planet" is different from the others because it is a natural celestial body that exists in outer space, while the other words refer to objects that are man-made or serve functional purposes in human environments. A remote control is a device used to operate electronics, a coat is an article of clothing worn for warmth or protection, and an elevator is a mechanical system used to transport people or goods between floors in a building. In contrast, a planet is a part of the universe and does not serve a functional role in everyday human activities, making it distinct from the other items listed.