QR Codes (or Quick Response Codes) are images which hold information, usually websites, which are readable by the camera on a smartphone. You can find them in magazines, flyers, manuals or on products.
Rather than typing in a URL just scan it in with your smartphone, and depending on the apps on your smartphone, it will bring you to the link.
QR Codes don't have to store URLs. You can send "secret" messages to your friends with QR Codes.
Right Click, then choose Save Image as...