To read and scan QR codes can be done in various ways. There are four options for scanning a QR code.
iOS devices: With the latest OS systems, you can open a camera and start scanning until a notification appears on your display.
Android and other mobile devices: If your smartphone supports the latest OS, you can apply the same strategy as on IOS devices. The only detail to look out for is to enable the QR code scanning on your device.
Desktops: Some desktops have in-built QR code scanners, or you can download an app that allows you to scan a code quickly.
Older OS: Download a separate QR Scanner from an app store to scan a QR code.