QR code (quick response code)

A QR code (quick response code) is a type of two dimensional (2D) bar code that is used to provide easy access to online information through the digital camera on a smartphone or tablet.

A barcode reader in the camera interprets the bar code, which typically contains a link to view a webpage, send an SMS text message or call a phone number. The technology for QR codes was developed by Densa-Wave, a Toyota subsidiary. The codes were originally used for tracking inventory and required a separate reader app, but beginning with iOS 11 and Android 8.0, readers are native to most mobile device cameras.

Here is an example of what a QR code looks like.

Static QR codes, like the one above, are typically used to disseminate information to the general public. They are often displayed on posters and billboards and in ads in newspapers and magazines. The person who created the code can track information about the number of times their code was scanned and whether or not the code's call to action was taken.

Dynamic QR codes (sometimes referred to as unique QR codes) offer more functionality. They can be edited at any time and even target a specific individual for personalized marketing. Such codes contain more metadata to facilitate tracking.