simple. a chip (IC or integraded circuit)
BUT if you wanting to know how its read from the RFID reader...
The tag is known as a passive transmitter.(it doesnt contain power)
The tag has a coil of wire inside known as an inductor which acts as an arial. The ID tag is powerless untill it is close to the reader, which activates the tag through magnetic radiation(radio waves). The ID tag then transmits all its data thats stored in its chip.
How is data stored in a rfid tag?
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Some think so, some think it’s an RFID tag.
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