A radio-frequency remote control, or RF remote, uses radio waves to transmit a signal to an electronic device. RF remotes are very common; they're used in devices such as garage door openers, remote control toys and remote car-entry key fobs.
An RF remote encodes commands in binary form. The commands are sent via the radio waves to devices on the receiving end -- say, a DVD player -- that decode the commands and send them to the right place (volume up/down, etc.). A useful feature of RF remotes that sets them apart from infrared (IR) remotes is they can transmit signals up to 100 feet (30.5 meters) and can travel through walls and furniture. IR remotes, however, can only go 30 feet (9 meters) and need line of sight.
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