NFC (near field communication) is a wireless technology which allows for the transfer data such as text or numbers between two NFC enable devices. Near-field communication devices operate at the same frequency (13.56 MHz) as HF RFID readers and tags.
The term NFC tag is commonly used for a passive NFC tag. Examples of passive NFC tags are NFC inlays, NFC stickers, NFC key fobs, NFC wristbands, NFC cards and other converter NFC products.
NFC tags are very similar to a USB stick, except that they do not have to be plugged into a PC to transfer data. There is no battery inside of NFC tags.
They all have an integrated circuit (IC) and antennae inside of them. Data is transferred via this antenna.