Cool Cat Teacher Blog: QR Code Classroom Implementation Guide
QR Codes (Quick Response Codes) are just barcodes. There is nothing fancy about them.
Just like the grocery store clerk uses barcodes to look up the product and scan the price into the computer, your mobile device or computer can look up QR codes to:
take you to a website,
read some text,
give you a phone number, or
generate a text message.