What are garage door openers? An opener, also referred to by the name of remote-controlled opener, can manually open and close a garage door by using the radio signal. Garage doors are controlled electronically, usually by a transmitter in the garage wall so that you won't need an actual key to open the door. A lot of garage doors have an electronic remote control that can be operated remotely to open or close the door. Certain garage doors can be operated via your mobile phone.