The term "semi-passive" generally refers to a system or device that is partly active and partly passive. In other words, it combines elements of both active and passive systems. This hybrid approach allows semi-passive RFID tags to benefit from some of the advantages of both active and passive systems. Specifically, they are partially powered and transmit data actively, like active RFID tags. Still, they also have some passive components that allow them to operate with a smaller battery and at a lower cost than fully active tags.