They are 3 types of rfid tag, active tag, passive tag and battery-assisted passive tag.
HOW RFID Tag Work?
RFID Active Tag
It is a transmitter with their own power source (typically a battery). The power source is used to run the microchip’s circuitry and to broadcast a signal to a reader (the way a cell phone transmits signals to a base station).
RFID Passive tag
It is an RFID tag that does not contain a battery; the power is supplied by the reader. When radio waves from the reader are encountered by a passive rfid tag, the coiled antenna within the tag forms a magnetic field. The tag draws power from it, energising the circuits in the tag.
RFID Battery-Assisted Passive (BAP) Tag
It is essentially passive RFID tags with an internal battery. The tag uses its battery to send the signal much farther than traditional passive RFID tags, ranging up to around 100 meters in an ideal setting.