Short for radio frequency identification, a RFID is a small tag that enable a store or company to keep track of inventory. The picture shows an example of the back of an RFID. You may have seen stickers similar to this on products you have purchased from the store.
In 1971, Mario Cardullo developed the first predecessor to today's RFID devices. Mario's device was a basic toll device, consisting of a passive radio transmitter with built-in memory, and was powered by an interrogating signal. The device was later patented by Mario Cardullo in January 1973.