With RFID, the electromagnetic or electrostatic coupling in the RF (radio frequency) portion of the electromagnetic spectrum is used to transmit signals.
Source: Webopedia
URL: http://www.webopedia.com/DidYouKnow/Computer_Science/2005/rfid.asp
Source: Webopedia
URL: http://www.webopedia.com/DidYouKnow/Computer_Science/2005/rfid.asp