Barcode

A barcode or bar code is a method of representing data in a visual, machine-readable symbolic form. Initially, barcodes represented data by varying the widths, spacings and sizes of parallel lines. These barcodes, commonly referred to as linear or one-dimensional (1D), can be scanned by optical scanners known as barcode readers. Later, two-dimensional (2D) variants were developed, using rectangles, dots, hexagons and other patterns, called matrix codes or 2D barcodes. Despite being often included as barcodes, these do not use bars as linear barcodes do. These can be read using purpose-built 2D optical scanners.