Two-dimensional code is also called two-dimensional bar code, and the common two-dimensional code is QR code, which means rapid response. It is a very popular coding method in mobile devices in recent years, which can store more information and represent more data types than traditional bar codes.
Two-dimensional code is a black-and-white graphic that records data symbol information and distributes on a plane (two-dimensional direction) according to certain geometric figures and certain rules. In coding, the concepts of "0" and "1" bit streams, which constitute the internal logic foundation of the computer, are skillfully used, and several geometric shapes corresponding to binary are used to represent the numerical information of characters, which can be automatically read by image input equipment or photoelectric scanning equipment to realize automatic information processing.