There are different types of RFID readers, with passive RFID readers being one of the most common variants. Passive RFID readers do not have an internal power source and rely on the energy emitted by the RFID tag to function. When an RFID tag comes within the range of a passive RFID reader, it energizes the tag, allowing the reader to read the data stored on it. Passive RFID readers are widely used in applications where cost-effectiveness and simplicity are important factors.
For more check - https://www.idsolutionsindia.c....om/product/rfid-read