The QR code consists of randomly scattered squares that create a two-dimensional code that can greatly facilitate the use of websites.
We read QR codes (Quick Response Code) using smartphones - just have the application installed and after launching direct the smartphone to the code, as they did the picture. The code is read and an operation coded in the code is implemented, e.g. opening a website saved in the code. Without the QR code, it would take much longer to find information.
QR codes are widely used, only imagination can limit you, which of course is not lacking in RON.PL