An additional distinguishing characteristic of RFID transponders is the way of activating them.

Active transponder or also called active tags are obtaining their energy for receiving the data and the operation of the microchip from a internal battery.  They can send out signals by their own, whereas passive transponders or passive tags obtaining their energy from a magnetic field respectively form electromagnetic waves that are send out by an RFID reader. Active RFID tags are often used in combination with  sensor technology that needs battery power to monitor physical properties.