A QR code (abbreviated from Quick Response code) is a specific matrix barcode (or two-dimensional code) that is readable by dedicated QR barcode readers and camera telephones. The code consists of black modules arranged in a square pattern on a white background. The information encoded may be text, URL, or other data.
Common in Japan, where it was created by Toyota subsidiary Denso-Wave in 1994, the QR code is one of the most popular types of two-dimensional barcodes. The QR code was designed to allow its contents to be decoded at high speed.
The technology has seen frequent use in Japan, the Netherlands, and South Korea, while the rest of the world has been slower in the adoption of QR codes.http://en.wikipedia.org/wiki/QR_code