NFC stands for "Near Field Communication." NFC Tags are typically little, flexible stickers that have some battery-free tech inside. Someone with a device that can interact with NFC simply holds their device close to the tag -- or touches their device to the tag -- in order to see the digital content from the tag itself. With Phy, you can set up and manage NFC Tags and fully control the content experience.
For more, see How do people see content through my NFC Tags?