QR code (Quick Response code) is a type of two-dimensional matrix code that can store information in the form of text or binary data. QR codes usually consist of small squares arranged in a specific pattern, and can be read by devices such as smartphone cameras or QR scanners.

QR codes are often used to track information about products in the supply chain and since many smartphones have built-in QR readers, they are often used in marketing and advertising campaigns. Recently, it has played a key role in helping track coronavirus exposure and slowing the spread of the virus. QR codes are two-dimensional graphic blocks that contain a monochromatic pattern representing a sequence of data. They are designed to scan or be scanned by cameras, including those found on cell phones, and are often used to encode Digital Asset Wallet addresses.