Bar Codes

Bar codes are a method of storing information graphically so that it can be read by a laser scanner. This allows information to be scanned into a computer using the laser scanner rather than having a human enter the information manually using a keyboard. Long strings of numbers and letters can be entered into the computer with one single scan of a bar code in a fraction of a second. Therefore, the primary purpose of a bar code is to eliminate the possibility of human data entry errors and to speed up data entry.

There are dozens of types of bar codes in use throughout the world today for a variety of purposes. UPC bar codes are one of the most common types of bar codes. The UPC code is the 12-digit numerical codes used on retail products in North America. Then there is the EAN bar code, which is the 13-digit bar code used on retail products throughout the rest of the world. There are PostNet bar codes used on U.S. Mail, SCC and SSCC codes used on product shipments, Code 39 and Code 128 used for a variety of purposes such as inventory tagging, and many more.

One way in which bar code types differ is the size of bar code required to store a given amount of information. To illustrate this concept, think of a bar code like a font. Using the Arial Narrow font, you can make the numbers 12345 look like this:

but using the Copperplate Gothic font you can make it look like this:

. Do you see how the Copperplate font requires much more space to display the number 12345 as compared to Arial Narrow?

The same holds true for bar codes. Take a look at the images below. We stored the exact same information (12345) in several types of bar codes:

Code 128	RSS/Databar	PDF417 Code	QR Code

Most bar codes appear as vertical lines, often in black on white. These bar codes are referred to as one-dimensional (or 1D) bar codes since they are read across. Other bar codes look like a checkerboard. These are called two-dimensional (2D) bar codes because they are read across and up/down at the same time. 2D bar codes are increasingly popular because of their capability to store large amounts of information in a very small space. However, 2D bar codes can only be read by newer model bar code scanners that have the ability to read both left/right and up/down at the same time.

Another differentiating factor between bar code types is their capability to store different type of information. Some codes store just numbers, others store both numbers & letters and yet other codes allow the encoding of all characters. Some bar code types only accept a certain number of digits. UPC bar codes, for example, encode exactly 12 numbers. EAN bar codes encode exactly 13 numbers. Interleaved 2 of 5 bar codes encode an even number of numerical digits.

For additional discussion on more specific bar code topics, please see the other sections of our bar code guide.

To request more information regarding barcodes in general or any of our services, please call us at 1-877-872-2060 (toll-free) or 1-404-885-6066.

Please note that this short tutorial was designed as an introduction for the lay person. It is not meant as a comprehensive guide to all of the capabilities, technical concerns, or other implications of bar codes.