Explanation:
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.
Proximity readers work by constantly emitting a short range radio frequency (RF) field. When a proximity card comes within range of this field, an integrated chip within the card is powered up and the chip transmits a card number back to the reader. Not all proximity cards are born equal though, and it is important that the differences are weighed up when making a decision about which technology to adopt.
Reference: https://www.abr.com/what-is-rfid-how-does-rfid-work/#:~:text=RFID%2…
https://www.ict.co/Choosing-Card-Technology