What is a QR Code?
Short for “Quick Response code,” QR codes are square barcodes first developed in Japan. Unlike traditional UPC barcodes, which are made up of a number of horizontal lines, a QR code can be captured more quickly and can contain more information.
QR codes are machine-readable labels — computers can understand them much more easily than they can understand text. QR codes are used for everything from tracking products to identifying items — typical tasks where they function as improved UPC barcodes.
However, QR codes aren’t just a stuffy technology used to track items in warehouses and scan products at the checkout counter. They’ve moved into the consumer realm, where they’re found all over the place on advertisements, business windows, product packaging, billboards on the side of the road, and even on some websites.
What’s the Point?
Typically, QR codes are captured with a scanner app on a smartphone. The app allows you to take a photo containing the barcode, then it locates the barcode, analyzes the machine-readable data, and converts it to information meaningful to you.
For example, you may see a barcode on a billboard, business window, or a product’s packaging. After being scanned in this way, a typical QR code would probably take you directly to the businesses’ website. In this case, the QR code contains a website address (URL.) The point of the QR code is to allow you to easily access their website without typing any web addresses into your phone — just by scanning a picture.
QR codes can also be used for other purposes. For example, when you set up Google Authenticator, Google’s two-factor authentication system, Google will show a QR code on your computer screen. This QR code can be scanned with the Google Authenticator app on your smartphone and your smartphone will automatically fill in your authenticator information. This is much more convenient than manually typing in an authentication code and checking to see if it was typed correctly.
In this case, a QR code is being used to allow a computer and smartphone to communicate with each other. They don’t have to initiate any sort of connection or even be on the same network — the smartphone just has to be able to capture the computer’s screen.
Are They Actually Useful?
QR codes do have their uses. They’re a low-tech solution that works on any device (as long as one of them has a camera), unlike more complicated technologies like NFC. The way QR codes make setting up Google Authenticator much easier validates their usefulness in certain circumstances, and they’re a more advanced technology than traditional UPC barcodes for businesses that need to track and identify products.
However, let’s be honest — most QR codes we encounter in our day-to-day lives are on billboards, business windows, pamphlets, and product packaging, and they haven’t taken the world by storm like advertisers and marketers would have liked them to. To use a QR code, someone has to have a dedicated barcode reader app on their phone, launch the app, and scan the barcode to visit the website. In the same time, they could just have typed a short URL for the website or performed a Google search for it. To make matters worse, scanning a QR code can be complicated by the need to capture it at the appropriate angle, with enough light for the camera to see it, and without camera movement.
QR codes actually have some security problems — it would be easy for an attacker to print a QR code with a malicious URL on a sticker and affix it over a QR code in a high-traffic area. A QR code redirects you to an URL in your mobile browser, so it would be possible to take the user to a phishing site or a page that exploited a vulnerability in their mobile operating system.
excerpts courtesy of how to geeks