A machine-readable code consisting of an array of black and white squares, typically used for storing URLs or other information for reading by the camera on a smart phone is known as QR Code or Quick Response Code.
QR Code Technology comes from Japan, where it was invented by a two member team of Denso Corporation. It is widely used today and easily read by any smart phone available in the market. They were developed to offset the capacity limitation of Barcodes. It can store up to 4,296 alphanumeric or 7,089 numeric characters, and depending on the level of error correction chosen, up to 30% of smudged data on the tag can be restored.