Remote control

A remote control is a device used to issue commands (controlling it) from a distance to televisions, DVD players, doorbells and so on. 
A remote controller does not have a wire and can be held by hand. It has buttons for volume, changing television channels and more.
Infrared or radio signals are used to communicate with the devices. Batteries make remote controls and controllers work. Mostly AAA, AA or coin battery size batteries are used.