Barcodes and QR-codes

A barcode is a visual representation of data that can be read by machines. The data usually describe something about the object that carries the barcode.

Traditional barcodes systematically represent data by varying the widths and spacing of parallel lines and may be referred to as linear or one-dimensional (1D). Two-dimensional (2D) variants use other geometric patterns. These are called matrix codes or 2D barcodes and can be read by 1D/2D- barcode readers or smartphones.