At least three types of labels are found in industrial settings today. 1D, or linear, barcodes are the familiar arrangement of black and white lines and spaces used to create the Universal Product Code (UPC). In a warehouse or manufacturing plant, a bar code may also be used for other purposes, like identifying a storage location in a rack system.

2D bar codes come in a variety of forms, but common to all is that information is encoded both vertically and horizontally. A 2D bar code is typically used when you need more information than can be contained in a 1D code. In the pharmaceutical industry, for instance, you might need a date and lot code in addition to a product code. Direct part marking is a technique for applying a unique identifier directly to a part that can be used in the future for tracking and tracing.

Laser scanners, which read 1D bar codes, are the most common. These devices read bar codes in conjunction with an oscillating mirror that automatically moves the beam back and forth across the bar code.  Imaging technology can also read 2D bar codes and direct part markings and is beginning to take a larger share of the market. Image systems capture an image of the bar code, much like a digital camera.