A barcode is an optical machine-readable representation of data relating to the object to which it is attached. Originally barcodes systematically represented data by varying the widths and spacing’s of parallel lines, and may be referred to as linear or one-dimensional (1D). Later they evolved into rectangles, dots, hexagons and other geometric patterns in two dimensions (2D). Although 2D systems use a variety of symbols such as “QR”, they are generally referred to as barcodes as well.
QR code (Quick Response Code) consists of black modules (square dots) arranged in a square grid on a white background, which can be read by an imaging device (such as a camera) and processed using Reed–Solomon error correction until the image can be appropriately interpreted. The required data are then extracted from patterns present in both horizontal and vertical components of the image.
The QR Code system has become popular due to its fast readability and greater storage capacity compared to standard UPC barcodes. With a camera phone equipped with the correct reader application, QR codes can be scanned to display text, contact information, connect to a wireless network, or open a web page in the telephone’s browser. Other uses include product tracking, item identification, time tracking, document management, general marketing, virtual stores, websites login, consumer advertising, commercial tracking, entertainment and transport ticketing, personal information storage.
QR codes can be used to store bank account information or credit card information, or they can be specifically designed to work with particular payment provider applications. Also, encrypted QR codes, which are not very common, can be used when issuing visa in passports.