Near field communication, also known as NFC, is a secure radio technology that enables two devices to wirelessly trade data when they are within about five centimeters of each other. NFC has been bandied about as the next big thing for mobile payments for several years, and it may finally be taking off. Juniper Research predicts that NFC-enabled payments will total $180 billion dollars by 2017. Here’s what you need to know about this new technology.