RFID systems consist of three main components: tags, readers and databases.
1) RFID Tags: RFID tags are small programmable devices used for object, animal and human tracking. RFID tags come in different shapes, sizes and functionalities. Whereas some tags are read-only devices, usually only storing an ID number, others are reprogrammable and capable of storing larger amounts of data. RFID tags communicate wirelessly with RFID readers and many are powered by the reader as well
2) RFID Readers: RFID readers acquire and sometimes rewrite information stored on RFID tags that come within operating range (a few inches up to several feet). Readers are usually connected to a computer system that records and formats the acquired information for further uses.
3) Computer Database: RFID databases vary widely depending on the intended future use of the logged information. Databases are usually designed in such a way that the information can be easily matched and merged with other information, a technique called computer matching.
Due to their small size, RFID tags can be placed in or on packaging materials, clothing, wristbands and—in the case of sub-dermal tags—under animal and human skin. RFID differs from existing electronic ID technologies (such as barcodes, magnetic stripes and smart cards) in several ways. Most importantly, RFID increases the amount of data that can be stored and transmits this information wirelessly and automatically whenever a tag is within range of a reader. This introduces new applications such as automatic checkout and identification at a distance.
The first cited use of RFID technology was by the British Royal Air Force
to identify "friendly" planes during WWII. Starting in the 1960s, bulky radio tags were used to track wildlife for scientific study. In the last two decades, however, electronic miniaturization has made "passive" RFID technology possible and increasingly inexpensive. The initial targets of passive RFID tracking were wildlife, but have since progressed to livestock, pets, cars, prisoners, packaged products, military hardware and school children. In October 2004, the FDA approved implantable RFID tags for injection into humans within the United States.
RFID is on the brink of mass deployment. The current cost of RFID tags is still too high for companies to fully embrace them, but the stated industry goal is to replace barcodes with RFID on most products within the next decade. Wal-Mart, the world's largest retailer, is leading the way by mandating its suppliers to adopt the Electronic Product Code (EPC) RFID standard on bulk packaging of products by January 2005. Given Wal-Mart's general market force and the rush for RFID implementation after the Wal-mart mandate, Preemptive Media has tailored its first series of Zapped! initiatives for the "Wal-Mart scene."