QR Codes have been invented a couple of decades ago in Japan. They are 2D barcodes that can pack a lot of information into a relatively small space. Also, their design makes them pretty resilient in case their support gets scratched. Since QR Codes are more and more used worldwide, knowing how to scan/decode them is very useful. In this article, we will be knowing – what is a QR Code and several ways to scan QR Codes.
What is a QR Code?
QR Code means “Quick Response code”. It is a machine-readable code that can be decoded only with the help of a smart device (phones, tablets, etc…) QR Codes are simply a representation of text information which has been encoded into a 2D barcode form.
They increase productivity because it’s faster to scan the code, than entering the information manually. QR Codes came into existence in 1994. It was invented by Denso Wave (a subsidiary of Toyota Industries).
Why are QR Codes used for?
There are many usages for QR Codes, the common ones are as follows:

Tracking Packages (Vehicle parts, product tracking etc.)
Pointing to URLs
Instantly add a vCard contact (virtual business card)
Making payment from a wallet app
Website Login
Point to an app download URL

How to scan QR codes on Android
There are tons of QR Code scanner applications available on the Play Store and most of them work as expected. However, we would be mentioning just one of the popular QR scanner apps for Android. Fret not, every QR code scanner app works (more or less) the same way.
QR Code Reader One of the most popular QR code scanner app. It can also scan product barcodes and let you know more about the pricing of a product. The app is 2.20 MB in size and has no known abnormal bugs at the time of publishing. It is completely free. Fortunately, it does not contain in-app advertisements.
However, to be able to scan all types of barcodes, you need to upgrade it to the pro version at 2 USD. Also, with the premium version installed, you get the ability to set the QR Codes to open on your default browser rather on the in-app browser.
Steps to use QR Code Reader
qr code reader android

Step #1: Install the app from the Play Store (no 3rd party stores!).
Step #2: Open the application.
Step #3: Now, you just need to point your device’s camera at the QR Code.

Note: Some QR Codes might direct you to malicious websites and tempt you to install unwanted applications.
Scan QR codes on iPhone/iPad
Similar to Android, iPhones or iOS powered devices do not have the built-in ability to scan QR codes. Apple Pay surely does scan QR codes and check out using it at Walmart retail stores (or similar partner stores). But, you cannot use it for anything other than payments.
The most loved QR scanner app for iOS devices – “Quick Scan – QR Code Reader”. Let us get to know how it works.
Steps to use Quick Scan
quick scan iOS

Step #1: Install the app from the App store.
Step #2: Hit the app icon to launch it.
Step #3: Now, you just need to point your device’s camera at the desired QR Code. So, it is pretty simple to use and the same way works on Android as well.

Scan QR Codes on PC
As the QR codes are being used almost everywhere (embedded in an image, directs you to download an app through a website, and tons more), there was a need to expand the functionality to scan QR codes even without a smartphone.
Should you buy a smartphone just to scan a QR code on the web? No, you do not.
There are several QR Code scanner software tools developed. CodeTwo QR Code desktop reader is one of them. It is a freeware (software that is available free of charge) for Windows. So, if you are a Mac user, you could try QR Journal. And, just in case, you are a Linux user, you can head to this forum thread to get started.
Steps to use CodeTwo QR Desktop Reader
code two qr code for windows

Step #1:Download the setup file from the official website.
Step #2: Open the setup file and follow the on-screen instructions to complete the installation.
Step #3: After you are done with the installation, launch the software.
Step #4: Choose the way you want to scan the code. Here, the tool offers two different ways with which you can work with QR Codes – from the screen and from a file.
Step #5: If you want to scan a QR Code that you observed on a website, email, and banner, you can select the option – “From screen” to scan the QR Code by highlighting it with the help of your cursor (similar to what you do with the clipping tool).
Step #6: If you have an image file downloaded, you can select the option – “From file” to select the desired file and scan it.

Scan QR Code – Barcode Scanner device
barcode scanner deviceIf you want a dedicated device to scan QR codes, there is nothing better than a QR / Barcode scanner device.The device would come handy if you are a physical retailer or have a role that needs you to scan codes regularly.
There are various manufacturers offering these devices. We would mention PegasusTech, Argox, and Honeywell as some of the recommended brands to get a code scanner device from.
Conclusion
There are several ways by which we can scan a QR Code. The most expensive way would be the barcode scanner device, and the easiest is the smartphone. If you are not equipped with a smartphone, you can do it on your PC as well.

http://www.topnetblog.com/2016/08/learn-how-to-scan-qr-codes.html