QR codes are two-dimensional bar codes that can contain any alphanumeric text and that often feature URLs that direct users to sites where they can learn about an object or place (a practice known as "mobile tagging"). Decoding software on tools such as camera phones interprets the codes, which are increasingly found in places such as product labels, billboards, and buildings, inviting passers-by to pull out their mobile phones and uncover the encoded information.
QR codes link the physical world with the virtual by providing on-the-spot access to descriptive language and online resources for objects and locations. In this way, the codes support experiential learning, bringing scholarship out of the classroom and into physical experience. The greatest importance of QR codes could lie not in their specific use but in the opportunities they offer for moving away from keyboards as input devices in learning environments.