A QR Code is a specific matrix barcode (or two-dimensional code), readable by dedicated QR barcode readers and camera phones. The code consists of black modules arranged in a square pattern on a white background. The information encoded can be text, URL or other data.

Common in Japan, where it was created by Toyota subsidiary Denso-Wave in 1994, the QR code is one of the most popular types of two-dimensional barcodes. QR is the abbreviation for Quick Response.

Although initially used for tracking parts in vehicle manufacturing, QR codes are now used in a much broader context, including both commercial tracking applications and convenience-oriented applications aimed at mobile phone users. QR codes can be used to display text to the user, to add a vCard contact to the user's device, to open a URL or to compose an email or text message. Users can also generate and print their own QR codes for others to scan and use by visiting one of several free QR code generating sites.

QR codes storing addresses and URLs may appear in magazines, on signs, buses, business cards, or on just about any object about which users might need information. Users with a camera phone equipped with the correct reader application can scan the image of the QR Code to display text, contact information, connect to a wireless network, or open a web page in the phone's browser. This act of linking from physical world objects is known as a hardlink or physical world hyperlinks.

Google's mobile Android operating system supports QR codes by natively including the barcode scanner (ZXing) on some models, and the browser supports URI redirection, which allows QR Codes to send metadata to existing applications on the device. Nokia's Symbian operating system is also provided with a barcode scanner, which is able to read QR codes, while mbarcode is a QR code reader for the Maemo operating system. In the Apple iOS, a QR code reader is not natively included, but over 50 free Apps are available with reader and metadata browser URL redirection capability. This technology is being adopted so fast, that by the time you read this, it will likely be a native capability in many mobile devices.

QR CODES IN MARKETING

Recently, QR codes have become more prevalent in marketing circles and have been integrated into both traditional and interactive campaigns. Media where QR codes have been deployed include: billboard ads, guerilla marketing campagns, in-store displays, event ticketing and tracking, trade-show management, business cards, print ads, contests, direct mail campaigns, websites, email marketing, and couponing just to name a few. QR codes are of particular interest to marketers, giving them the "ability to measure response rates with a high degree of precision" allowing for easier ROI (return on investment) calculation, thus helping justify spending on marketing budgets. QR codes have also been used at trade shows and in conferences.