Meet the QR Code. It is similar in function to a barcode, but it can store a lot more information in it. It stores information in two different directions (horizontal and vertical). Therefore, you don't have to line up a scanner to scan it. Additionally, it can be missing as much as 7% - 30% of the information (depending on the error correction used) and still recover!
In 1994 the automotive industry in Japan introduced it. Since then it has become very popular in many other industries and all over the world. It really shines as a way to get visitors to a certain location (like a website). I have seen them at museums, in airports, and even on Board Game Instruction Manuals!
How do you view them? I'm glad that you asked (and even if you didn't just play along).
Well, years ago when they were much newer you had to download a special QR Code reading app to your phone. The app required permission to access your device's camera. It would take and process a picture to find any bar codes found in it. Today it is a standard feature of most smartphones. In fact, the Google camera app can natively process them. Just point your phone at the QR Code with the app open, and it will automatically read it with a hint on the bottom.
So how does one get a QR code you ask (are we on the same wavelength or what)? There are many free websites that you gladly generate one for you. All of the ones that I visited allow you to use their QR Code generator for free. You can even use the result commercially. How they make their money is by subscription services and customization.QR Codes can be made to look quite fancy. You can embed logos, colorize, and add fancy borders.
Another thing to consider is a Static URL versus a Dynamic URL. With a static URL the QR Code points directly to the target link. What happens in the future if the link goes down or you move your website? It might be costly or impractical to have to reprint the QR Codes later. By pointing to a Dynamic URL you will be immediately redirected to the target link. Now the URL can be shortened and even changed later on. The only real downside is that you are now at the mercy of the company hosting your URL redirector. Do they require a yearly fee? What if their service goes down?