About QR barcodes in general

A QR code (abbreviated from Quick Response code) is a type of matrix barcode (or two-dimensional code) first designed for the automotive industry. More recently, the system has become popular outside of the industry due to its fast readability and comparatively large storage capacity. The code consists of black modules arranged in a square pattern on a white background. The information encoded can be made up of any kind of data (e.g., binary, alphanumeric, or Kanji symbols). Although initially used to track parts in vehicle manufacturing, QR codes are now (as of 2011[update]) used over a much wider range of applications, including commercial tracking, entertainment and transport ticketing, product marketing and in-store product labeling.