What are garage door openers? An opener, also referred to by the name remote-controlled opener, allows you to manually open and close a garage door using an electronic signal. Garage doors are controlled electronically via a transmitter installed on the garage wall. This means that you don't need to carry a key in order to open or close the door. They also have a small handheld electronic remote control, which is used to open and shut the door from an extended distance. In addition certain garage doors can even be operated using your cell phone.