A QR code is an image consisting of a unique combination of square blocks. You can read the QR code with a QR code scanner (which is now standardly built into the camera function of your smartphone). When you scan the code, you are redirected to an online location (e.g., a website). You can also use a QR code to link to a payment method or to transmit all the data for a payment without having to type it in.
In Billit, you will find three types of QR codes: