Radio frequency identification (RFID) tags are unique labels that contain special high frequency (HF) or ultra high frequency (UHF) antennas. This technology is ideal for identifying and tracking purposes and can be easily and inexpensively produced and incorporated into many different products. Whether it's a product you buy at the grocery store or a security device inside the pages of your passport, RFID technology is everywhere. Global Industry Analysts has projected that the world RFID market will hit USD 18.7 bn by 2017, so it's certainly here to stay.
RFID tags can be divided into two distinct types: active RFID and passive RFID.
Active RFID tags are battery powered and can transmit signals over 100 feet. They are generally used to track high end goods like vehicles and shipping containers.
Passive RFID tags don't contain batteries, but instead take their power source from the reader. They typically transmit their signal over a distance of less than 10 feet. These types of tags are very cheap and are therefore ideal for tracking lower cost items, such as those you might find in a store.