RFID technology

Radio-frequency identification (RFID) is the use of an object (typically referred to as an RFID tag) applied to or incorporated into a product, animal, or person for the purpose of identification and tracking using radio waves. Some tags can be read from several meters away and beyond the line of sight of the reader.

Radio-frequency identification comprises interrogators (also known as readers), and tags (also known as labels).
   
Most RFID tags contain at least two parts. One is an integrated circuid for storing and processing information, modulaiting and demodulaiting a radio-frequency (RF) signal, and other specialized functions. The second is an antenna  for receiving and transmitting the signal.
There are generally three types of RFID tags: active RFID tags, which contain a battery and can transmit signals autonomously, passive RFID tags, which have no battery and require an external source to provoke signal transmission, and battery assisted passive (BAP) RFID tags, which require an external source to wake up but have significant higher forward link capability providing greater range.
There are a variety of groups defining standards and regulating the use of RFID, including: international ograninization for standartization(ISO);

RFID has many applications; for example, it is used in enterprise supplay chain managment to improve the efficiency of inventory tracking and management.