A handheld remote control that can turn on and operate any unit of equipment in a home theater system, such as an A/V receiver, cable box, TV, DVR, CD/DVD player and media hub. It uses built-in remote control codes for different models and may be able to download additional code sets from the Internet. Advanced units have a training mode that accepts signals from another remote placed head to head and assigns them to designated buttons. See IR remote control and RF remote control.