QR CODE (Quick Response Code) consists of black squares arranged in a square grid on a white background, which can be read by an imaging device such as a camera. A QR code (quick response code) is a type of 2D bar code that is used to provide easy access to information through a smartphone or dedicated QR reading devices.
2D Barcodes or QR Codes are different in that the data is stored in both directions and can be scanned vertically OR horizontally.
Standard 1D Barcode (UPC/EAN) stores up to 30 numbers, but QR bar code can be as large as 177 by 177, allowing for 31,329 dots. That is enough space for about 3kB. QR Code offers more data storage than linear (1D) barcodes, up to 2,953 bytes, 4,296 alphanumeric or 7,089 numeric digits, and includes Error Correction Code (ECC) for error-free reading even when a symbol is partially lost or destroyed.
Any URL can be encoded into a QR Code so essentially any webpage can be opened automatically as a result of scanning the barcode. In addition to website URLs a QR Code can also contain a phone number, so when it is scanned it prompts the user to call a particular number. Similarly you can encode an SMS text message, V-card data or just plain alphanumeric text. The smartphone or 2D barcode reading device will automatically know which application to use to open the content embedded within the QR Code.