NFC (Near Field Communication) are passive and draw power from your smart phone. NFC tags come in a variety of sizes and material. Unlike barcodes or QR codes, no additional application is required. Most smart phones are equipped with NFC tag readers. Open files, connect to a WIFI, open applications, add contact information, set parameters all with just a tap from your phone. You have likely used NFC technology when paying for a product or service with a tap of smart phone.