Basically, a QR code is data encrypted as an image.
When you use your QR Code Scan, it will get you to the content it is linked to.
It can be a specific url outside the app, an image, text or anything.
For those who don’t know what is a QR Code, it looks like this:
If you were to scan this on your mobile device, it would take you to google.com.
Note: Each and every QR Code is different and relates to specific content that is set to link to it when a qr code is generated.