The printed code used for recognition by a bar code scanner (bar code reader). The "bar" in bar code comes from the ubiquitous, one-dimensional (1D) UPC bar code found on countless product packages. Several two-dimensional (2D) bar codes are also in wide use, but they are not really as bar-like as the UPC. The 2D codes are scanned horizontally and vertically and hold considerably more data. All the 2D examples below contain the same data: the URL for www.computerlanguage.com. See bar code scanner, mobile tagging, point of sale and AIM. Contrast with RFID.
1D Bar Code
One-dimensional (1D) UPC bar codes are used on millions of consumer items as well as shipping containers. For more details, see UPC
Symbol Technologies' PDF417 is a general-purpose bar code that contains up to 1,850 alphanumeric and 2,710 numeric characters. It is recognizable by patterns of vertical lines on each side. For more details, see PDF417
The DataMatrix code is used to mark small parts and holds up to 2,355 alphanumeric and 3,116 numeric characters. It is recognizable by its border with two solid lines and two alternating lines.
2D QR Code
The QR code is used to mark products as well as identify establishments. It is recognizable by its four squares with dots in the middle and holds up to 4,296 alphanumeric and 7,089 numeric characters. For more details, see QR code
The MaxiCode uses hexagonal symbols and is recognizable by its center bull's eye. Used for high-speed sorting, it holds up to 93 alphanumeric and 138 numeric characters. For more data, MaxiCodes can be chained together. (Image courtesy of AIM, Warrendale, PA, www.aimglobal.org)
Designed for mobile tagging, the Swiss-based BeeTagg system allows a company logo to be displayed in the tag's center. Recognizable by its honeycomb-like cells, BeeTaggs are also used for exchanging business card data. Sweden's largest newspaper uses BeeTaggs to link editorials with movies. For more information, visit www.beetagg.com. See mobile tagging
2D Microsoft Tag
Designed for mobile tagging, Microsoft's system uses color. Another form of the tag allows a company logo to occupy the background. See Microsoft Tag