A QR (abbreviated from Quick Response) code is a type of barcode that is initially invented in 1994 for the Japanese automotive industry to track materials. It stores information as a series of pixels in a square-shaped grid that can be read easily by a digital device.
Because of capability of storing lots of data and allowing users to access information instantly, QR codes are used in almost every area of daily life. They are showing up everywhere.
Source Jadranko Terzic