A cordless tool or device requires power to work but doesn't use wall-outlet electricity. Drills, vacuum cleaners, hair dryers, and irons can all be cordless, often by using rechargeable batteries. Since cordless appliances don't need to be attached to an outlet, they are more mobile and handy. Telephones were first available in cordless versions in the 1980's — before that, the handset was always attached to a base by a cord.