NFC allow information exchanges
NFC (or Near Field Communication) is a technology allowing two devices to exchange information, by bringing them close from each other.
The technology used is similar to the one deployed since the year 2000 inside contactless smartcards. Primary use cases include payment, but also transportation, or facilitated Bluetooth pairing.NFC signals are carried by a 13.56MHz frequency. It is leveraging inductive coupling between the antennas that are positioned on the two devices that exchange information. At moment during an information exchange, one device operates in the reader/writer mode. While the other one is in the card emulation mode. The device that operates in the reader/writer mode generates a field. It will communicate with the other device using ASK based signaling. The device that operates in the card mode will receive from the reader/writer enough power to ensure its ability to operate correctly. It will load/unload the field to form a signal that is understandable by the other party.
The communication speed in NFC is defined up to 424kbit/s (other available speeds are 212 and 106kbit/s), but the ISO 14443 specifications, on which NFC is based, has already defined communication speeds up to 6.8Mbit/s for VHBR (very high baud rate) ASK, or even 26Mbit/s for the more experimental VHBR PSK.

What are the use cases for NFC technology?
As NFC technology is evolving, you will find more and more use cases in mobile applications. Today NFC is involved in contactless payment, transportation, Fast Bluetooth and Wifi Pairing, Phone-to-Phone communication.
A huge range of peripherals such as smartwatches, wristbands, speakers and home appliances are embedded NFC technology too.