Ok, you have probably seen them and if you have the proper app you may have even scanned one using your mobile phone. QR codes or 2D barcodes are like product barcodes on packaging where a series of lines or squares (in this case) represent information. In the case of QR codes this information is used to connect the person scanning the code to a website or other internet address, display text, send a text message or fill out a virtual address card (Vcard).
The QR barcode was developed in 1994 by Denso-Wave a subsidiary of Toyota as a way to quickly scan a larger amount of data than a typical barcode could store. It is now a worldwide standard and its uses have grown from its manufacturing and inventory control roots to a potentially useful marketing tool. It is worth a look to see if QR codes have a place in marketing your art.