Learn in the textbookSerial and Short-Range Wireless Interfaces
DefinitionIrDA is a wireless standard in which devices send and receive data over infrared light (赤外線) at short range, about 1 m.
ExplanationInfrared is a form of light that travels in straight lines, so the transmitter and receiver must face each other with nothing in between. It was once used to exchange data between laptops and handheld information devices.
AnalogyLike a TV remote, it is a light signal that does not get through unless you point it the right way.
Memory hookShort for Infrared Data Association, the body that set the standard, whose name became the standard's name. "Ir" stands for infrared.