Have you ever entered a hotel room by swiping a card? If yes, it would be because radio waves from the card were able to identify and unlock the door, instead of using a key.

This technology uses a radio frequency identification (RFID) system and it has a wide variety of applications ranging from livestock tracking and FASTag to supply chain and inventory management. RFID-based FASTag payment system was made mandatory by the National Highway Authority of India in 2019. It was first introduced in 2014.