barcoding

Barcoding is a method of representing data in a visual pattern of bars and spaces that can be read by optical scanners. Barcodes are used to identify items, enable automated data capture, and support logistics, inventory, and point-of-sale operations. Modern barcodes come in two main forms: one-dimensional (1D) barcodes, which encode data along a single row of bars and spaces, and two-dimensional (2D) barcodes, which store information in patterns that may be read omnidirectionally, including squares or grids.

Common 1D symbologies include UPC-A and EAN-13 for product identification, Code 39 and Code 128 for alphanumeric data, and Interleaved 2 of 5 for industrial use. 2D barcodes such as QR codes, Data Matrix, and PDF417 can hold larger data sets and often include error correction.

Barcodes are standardized and managed by governing bodies such as GS1. The GS1 system uses identifiers like GTIN for products, GLN for locations, and SSCC for shipments; many 1D barcodes encode a GTIN. ISO/IEC standards specify the syntax and imaging requirements for many symbologies, while logos and application identifiers (AIs) allow additional data to be encoded within a single symbol.

In operation, a barcode is printed on an item or tag and scanned by a laser or image-based reader. The scanner decodes the pattern into numeric or alphanumeric data and forwards it to a computer system for lookup, validation, or inventory updates.

Barcoding is widely used in retail, manufacturing, logistics, healthcare, libraries, and asset management to speed transactions, improve accuracy, and enable real-time data collection. Limitations include dependence on line-of-sight, print quality, and environmental wear, and higher data-density requirements for 2D codes may require cameras rather than laser scanners.