QR, or Quick Response codes, unlike barcodes which scan right to left or vice versa, are two dimensional. As a result they enable significantly more information to be included in the QR icon. Originally developed in Japan by a Toyota subsidiary were used initially as a tracking mechanism. Because of this capability to embed considerable amounts of information combined with the capability of phones to both capture this information for encoding whilst at the same time to also read codes means that QR codes are quickly becoming mainstream.
Teachers such as Jarrod Robinson have been doing pioneering work working with QR codes across the curriculum. This article from searchengineland is a great introduction to the wider world of QR codes.
You’ve probably seen them in newspapers, magazines or other paper-based publications: two-dimensional bar codes, called quick response codes (QR codes). What are they? They have been described as paper-based hyperlinks, and this is a good description. You simply take a picture of a QR code with your smart phone, and you get redirected to a website using your cell phone’s browser. They can also be used digitally—you can append a QR code to a Tweet, or they can be displayed on a web page to transfer contact information directly to a cell phone, for example. This technology is blurring the distinction between smart phones, digital destination and content, and paper-based communication mediums.