<P> Radio - frequency identification ( RFID ) uses electromagnetic fields to automatically identify and track tags attached to objects . The tags contain electronically - stored information . Passive tags collect energy from a nearby RFID reader 's interrogating radio waves . Active tags have a local power source ( such as a battery ) and may operate hundreds of meters from the RFID reader . Unlike a barcode , the tag need not be within the line of sight of the reader , so it may be embedded in the tracked object . RFID is one method for Automatic Identification and Data Capture ( AIDC ) . </P>
rfid tags and bar codes are used in which process
to automatically identify and track tags attached to objects