Radio-frequency identification - Wikipedia
https://en.wikipedia.org/wiki/Radio-frequency_identification
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...
What is RFID and How Does RFID Work? - AB&R
https://www.abr.com/what-is-rfid-how-does-rfid-work/
RFID is an acronym for "radio-frequency identification" and refers to a technology whereby digital data encoded in RFID tags or smart labels (defined below) are captured by a reader via radio waves.