Bar/QR codes are machine-readable codes represented visually as numbers and parallel lines. When scanned by the optical sensor (laser or camera) of a scanner, these symbols produce a unique digital code. Codes are affixed to and associated with products to identify and distinguish them.
Barcode is a printed series of parallel bars or lines of varying width that is used for entering data into a computer system. The bars are typically black on a white background, and their width and quantity vary according to application.
A QR code (Quick Response code) is an array of black and white squares or pixels set in a grid that stores data for a machine to read. A smartphone or camera can quickly process the information contained in a QR code's specific arrangement of pixels, making it a convenient way to store and access data.