What is QR Code?
If you have a smartphone, most likely you can scan and read QR codes with the click of a camera. A QR Code, short for "Quick Response Code", is a two-dimensional bar code that looks like this and usually stores URLs:
Install an appropriate QR scanner/reader app for your phone type (search for "QR code scanner or "QR code reader" in the app market), and begin scanning and reading QR Codes whenever you see them.