A QR Code (Quick Response Barcode) is a system for storing information in an array of points or a two-dimensional bar code, are characterized by the three squares that are in the corners and to detect the position of the code lector. It is a barcode that can be read using a mobile phone through your camera. It is very useful for communicating an address or contact details, just enough to pass a phone or other device with a camera above the code and update our agenda and contact details directly to our mobile phone.
Today almost all mobile phones can read these codes, however it is possible that your mobile is not installed.
You can download a QR code reader: