Retractable roofs are sometimes known as "operable roofs" or "retractable skylights." Retractable roofs are utilized in apartments, restaurants, bars, swimming pools, and other facilities that want to offer an open-air experience at the touch of a button. They can be opened for enjoyment during warm-weather months or closed against inclement weather. Retractable roofs use glass or plastic panels that can be rolled up into a tube or collapsed onto a frame. When extended, they provide broad, sunlit areas where people can eat outdoors, by a pool, or around a fire pit. When retracted, the panels fold out of the way to allow rain or snow to pass through while protecting the outdoor area from the elements. Retractable roofs are used instead of conventional doors or windows because they are easier to seal off from the outside world when not in use. This makes them safer than opening up what would otherwise be a vulnerable space to the outside environment. Retractable roofs are operated by either electricity or gas. Electric retractable roofs require little maintenance and can be programmed to open or close automatically depending on the temperature or sunlight availability. They can also be programmed to come down at certain times of the day or night when it is dark outside. Gas-powered retractable roofs require constant monitoring but cannot be controlled remotely.