So what is a QR Code? A QR Code is a two-dimensional matrix barcode that is scanned by smartphones or bar code readers. The information encoded can link to a website, provide text, give a phone number or other data.
Watch the Common Craft video to understand more about QR Codes.
http://www.commoncraft.com/video/qr-codes
Check out how to get started and more QR resources at link below: