Basically, there are two types of remote controls for all kinds of electrical equipments which include infrared remote (IR) control and radio frequency (RF) remote control. Out of these, infrared remote controls send pulses of infrared light to the device and radio frequency remote controls make use of radio waves for this purpose. The range which you can get from both these kinds of remote controls creates a big difference in them. IR remote controls can only work on a line of sight principle and give you the range of around 30 feet. RF remote control can easily go through various walls and corners and give you a range of nearly 100 meters.
Most of the home appliances such as televisions, home theater sets and stereos are run by IR remote controls. There is an internal circuit board and there is a light emitting diodes in these remote control sets. As soon as you push any button of the remote, a corresponding code is transmitted to the receiving device with LED infrared impulses. Light from the LED is modulated with the control code pulses. Hence, receiver of the component receives pulses of the light and the flashes are decoded into digital bits which are necessary to activate this function. You can find some remote controls to be very finicky as they require pointing the remote directly at the component.
When you are trying to operate remote control but are unable to access component due to problem in line of sight, you can point it towards the flanking wall so light reflected from walls can reach the receiver. However, if an expanded range is needed RF remote controls are used for the components. Garage door openers, alarm systems and radio controlled toys make use of these systems. It is because RF remote controls are more convenient in usage as compared to IR remotes.
