RFID Technology definition is Radio Frequency Identification. It transmit RF signal by air to form one waterdrop type RF field where RFID tag enter and then get energy to start working, like returning tag number to RFID reader.
RFID has LF RFID, HF RFID and UHF RFID.
LF RFID is working on 125-134.2KHz
HF RFID is working on 13.56MHz
UHF RFID is working on 860-960MHz
UHF RFID can read more than 10 meters and can read 100 pcs RFID tag/second.
Thus UHF RFID can be used widely in many applications project, like logistic, warehouse, animal tracking, asset management, library book management etc.