Traditional barcodes consist of a series of parallel black lines with a series of numbers beneath the lines. The barcode encodes information specific to a company and product. The barcodes in North America, formerly called Universal Product Number code (UPC), are encoded with a 12 number code that includes a six to 10 digit company code.
Radio frequency identification (RFID) tags are microscopic programmable transponder tags that become activated when they come within range of an antenna that emits radio frequency signals. A transceiver of some sort is required to read the encoded information stored within the tag. Active RFID tags require batteries for power. Passive RFID tags get their power from the signal interaction of their built-in antenna and the reading transceiver.
RFID has been controversial due to privacy issues. Stores using RFID tags in products don't always deactivate the tag before the customer leaves the store. The tag remains readable for transceiver devices.
Bokodes are a barcode alternative designed by a team of researchers at the Massachusetts Institute of Technology (MIT). With a diameter of a mere 3 millimeters, bokodes work by placing an LED light behind a lens and a printed photomask. The desired information is printed on the photomask and readable with a standard cell phone camera from up to 12 feet away. Bokodes hold several thousand times the amount of information that a traditional barcode holds.
A grocery store bokode might display the product's price, nutritional information, and a comparison to other products on the shelves. The current cost of bokodes makes it unlikely they will completely replace barcodes but a cheaper alternative that replaces the light with reflective material is in the works.
Quick response codes, or QR Codes, began in Japan where they have become popular. A QR code is a square image made of pixels. A cell phone loaded with a QR reader application can take a picture of the code and retrieve the embedded information. The information can include a web link, contact information, and can automatically send a free text message or dial an embedded phone number.
QR codes took another step forward with the release of Microsoft Tag. The Tag systems allows for customizable pixellated images to reflect the user's personal style. Tag also allows business users to track analytic data about accesses to the business' code.