In a RFID system, the transponder which contains the data to be transmitted is called an RFID tag.
It is a microchip attached to an antenna that is packaged in a way that it can be applied to an object. The tag picks up signals from and sends signals to a reader. The tag contains a unique serial number but may have other information, such as a customer's' account number. Tags come in many forms, such smart labels that can have a bar code printed on it, or the tag can simply be mounted inside a carton or embedded in plastic.
RFID tag is a small device with a memory chip and antenna. Their tiny form and low cost make them irreplaceable in many cases where bulky Bluetooth tags cannot help. GearTags are battery-free Tracking Tags , they may last for years