A bar code (also barcode) is a optical machine-readable representation of data. Originally, bar codes represented data in the widths (lines) and the spacings of parallel lines and may be referred to as linear or 1D ( 1 dimensional) bar codes or symbologies. But they also come in patterns of squares, dots, hexagons and other geometric patterns within images termed 2D (2 dimensional) matrix codes or symbologies. It is important to note that both the patterns (lines, squares, dots, etc.) and spacings constitute the data encodation schema.
