The full form of QR code is "Quick Response Code". It is a type of two-dimensional matrix barcode that contains a matrix of dots arranged in a square grid. QR codes can be read both horizontally and vertically by an imaging device such as a camera, smartphone with a built-in camera, or QR scanner. They were first designed or invented in Japan in 1994 by a company called Denso Wave for labelling automobile parts. QR codes can store a lot of data, and they are frequently used to display text, open a webpage, add a contact, connect to a wireless network, or compose an email or text message. They have become common in consumer advertising and are often used in marketing and advertising campaigns. QR codes are also used in supply chain management and have played a key role in helping to trace coronavirus exposure and slow the spread of the virus.