What is RFID?

Radio-Frequency Identification (RFID) is the use of radio waves to read and capture information stored on a tag attached to an object.  A tag can be read from up to several feet away and does not need to be within direct line-of-sight of the reader to be tracked.

How does a RFID system work?

A RFID system is made up of two parts: a tag or label and a reader. RFID tags or labels are embedded with a transmitter and a receiver. The RFID component on the tags have two parts:

  • a microchip that stores and processes information


  • and an antenna to receive and transmit a signal

The tag contains the specific serial number for one specific object.

To read the information encoded on a tag, a two-way radio transmitter-receiver called an interrogator or reader emits a signal to the tag using an antenna. The tag responds with the information written in its memory bank. The interrogator will then transmit the read results to an RFID computer program.


There are two types of RFID tags: passive and battery powered.  A passive RFID tag will use the interrogator’s radio wave energy to relay its stored information back to the interrogator.  A batter powered RFID tag is embedded with a small battery that powers the relay of information.

In a retail setting, RFID tags may be attached to articles of clothing. When an inventory associate uses a handheld RFID reader to scan a shelf of jeans, the associate is able to differentiate between two pairs of identical jeans based upon the information stored on the RFID tag.  Each pair will have its own serial number.

With one pass of the handheld RFID reader, the associate can not only find a specific pair, but they can tell how many of each pair are on the shelf and which pairs need to be replenished. The associate can learn all of this information without having to scan each individual item.

RFID technology has been around since 1970, but until recently, it has been too expensive to use on a large scale. Originally, RFID tags were used to track large items, like cows, railroad cars and airline luggage, that were shipped over long distances. These original tags, called inductively coupled RFID tags, were complex systems of metal coils, antennae and glass.


Let’s look at a real-world scenario of this system:

  • At the grocery store, you buy a carton of milk. The milk containers will have an RFID tag that stores the milk’s expiration date and price.


  • As you exit the store, you pass through doors with an embedded tag reader.


  • Once you get home, you put your milk in the refrigerator, which is also equipped with a tag reader. This smart refrigerator is capable of tracking all of the groceries stored in it.


  • Products are also tracked when they are thrown into a trash can or recycle


RFID Criticism

As with many new technologies, people fear what they don’t understand. In the case of RFID, consumers have many fears, some of which may be justified.

Human chipping has seemingly higher stakes than merchandise tagging, and RFID critics are concerned that human chipping may one day become mandatory. When the company CityWatcher.com chipped two of its employees in 2006, these fears spun out of control.