Radio-frequency identification (RFID) uses electromagnetic fields to automatically identify and track tags that are attached to objects. The tag contains electronically stored information which can be read from up to several meters away. Unlike NFC which requires close proximity, RFID can work over greater distances; therefore, Bluetooth and NFC, while also wireless communication technologies, are not the correct answers as they serve different purposes and operate differently. Barcodes require a visual scanner to read information, which differs from RFID's radio frequency method.