A barcode is an optically readable representation of data. Barcodes represent data in the width and the spacing of parallel lines—these are commonly referred to as linear or 1D (1 dimensional) barcodes or symbologies. Barcodes also come in patterns of squares, dots, hexagons and other geometric patterns within images which are commonly referred to as 2D (2 dimensional) matrix codes or symbologies. Barcodes can be read by optical scanners called barcode scanners or barcode readers or scanned from an image using specialized software.Note
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Although 2D systems use symbols rather than bars, they are still referred to as barcodes.
Symbologies
The mapping between messages and barcodes is called a symbology. The specification of a symbology includes the encoding of the single digits/characters of the message as well as the start and stop markers into bars and spaces, the size of the quiet zone required before and after the barcode, and the computation of a checksum.
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