Radio frequency identification (RFID) is a form of wireless communication that uses radio waves to identify and track objects. RFID takes the barcoding concept and digitizes it for the modern world providing the ability to:
Uniquely identify an individual item beyond just its product type
Identify items without direct line-of-sight
Identify many items (up to 1,000s) simultaneously
Identify items within a vicinity of between a few centimeters to several meters