RFID is Radio Frequency Identification.It's also be called electronic tag.

What is RFID Technology?
RFID is a contactless automatic identification technology, it automatically identify target and get the data with radio frequency signal,it can work in all kinds of bad environment and without intervention when work. RFID technology can identify the high-speed moving objects and can identify multiple tags at the same time, fast and convenient operation.

RFID is a kind of simple wireless system.It include two basic devices.It used for control,detection,tracking target.The system is composed of reader and a lot of tags.

RFID Category
It's can be divided into LF(125KHZ),HF(13.56MHz),UHF(860~960MHz) with Frequency,and it can be divided into passive and active.Passive RFID reading/writing distance is shorter,and the price is low.The active RFID reading/writing distance is long,but it was powered by batteries,the cost is higher.

Component RFID
    Label (Tag) : consists of coupling components and chips, each Tag has a unique electronic coding, attached to the object identified target;
    Reader,the device of read or write the tag,divided into handheld and stationary
    Antenna,transfer signal between reader and tag