QR codes, or Quick Response codes, are a type of two-dimensional barcode that can be read using smartphones or dedicated QR reading devices. They were originally developed in Japan in 1994 by Denso Wave, a subsidiary of Toyota, for tracking automotive parts during manufacturing. However, due to their ability to store more information than traditional barcodes and the ease of reading them using mobile phones, their use has become widespread in various fields.

QR codes are composed of squares arranged on a square grid. The data in a QR code is stored in a series of pixels in the squares, and can represent numbers, text, or other data types.