RFID Tags
RFID tags are available in three configurations:
Passive tags have no internal power source, but they draw power from the reader. These are usually the most inexpensive tags and are often disposable.
Active tags contain a battery used for transmitting and are usually more expensive but can often be reused.
Semi-passive, a hybrid of passive and active, use a battery to operate the RFID chip, but communicate using power from the reader.