RFID Radio Frequency Identification abbreviation, that is, Radio Frequency Identification technology, commonly known as electronic tags.

RFID radio frequency identification is a non-contact automatic identification technology, it automatically identifies the target through radio frequency signal and obtain relevant data, identification work without manual intervention, can work in a variety of harsh environment.  RFID technology can identify high-speed moving objects and identify multiple tags at the same time, fast and convenient operation.

The most basic RFID system consists of three parts:

Tag: composed of coupling components and chips, each Tag has a unique electronic code, attached to the object to identify the target object;

Reader: A device that reads (and sometimes writes) label information;

Antenna: Transmits radio frequency signals between a tag and a reader.

Hong Kong is the first place in the world to use this technology in a public transport fare system.  The Octopus system uses Sony's 13.56 MHz FeliCa RFID chip and other related technologies.  Octopus's contactless smart card design allows users to conduct transactions simply by approaching the Octopus reader, without the need for direct physical contact (such as inserting the whole card into the reader).  Data transmission speed is 212 kbits per second.