QR codes, also known as 2-D codes or matrix barcodes, are codes that you can scan with a decoding app that uses your mobile device's camera. QR is short for quick response. Because they are more complex than line-based UPC barcodes, QR codes can accomplish many tasks, for example:
QR codes were invented in Japan in 1994, and are slowly increasing in popularity in the U.S. To read more about them, visit Wikipedia.