Radio-frequency identification (RFID) uses electromagnetic fields to automatically identify and track tags attached to objects. An RFID system consists of a tiny radio transponder, a radio receiver and transmitter. When triggered by an electromagnetic interrogation pulse from a nearby Radio frequency identification reader device, the tag transmits digital data, usually an identifying inventory number, back to the reader. This number can be used to track inventory goods.
Passive tags are powered by energy from the RFID reader’s interrogating radio waves. Active tags are powered by a battery and thus can be read at a greater range from the RFID reader, up to hundreds of meters.
Unlike a barcode, the tag does not need to be within the line of sight of the reader, so it may be embedded in the tracked object. Radio Frequency identification is one method of automatic identification and data capture (AIDC).
RFID tags are used in many industries. For example, a tag attached to an automobile during production can be used to track its progress through the assembly line, RFID-tagged pharmaceuticals can be tracked through warehouses, and implanting microchips in livestock and pets enables positive identification of animals. Tags can also be used in shops to expedite checkout, and to prevent theft by customers and employees.
