What is a key application of QR codes?

The correct application of QR codes is their ability to quickly link users to websites through scanning. QR codes, or Quick Response codes, are designed to be easily readable by devices such as smartphones. When a user scans a QR code, the device's camera interprets the code and can quickly redirect the user to a URL. This functionality makes accessing websites much more convenient, eliminating the need for manual entry of lengthy web addresses.

This capability is particularly valuable in various scenarios, such as marketing, ticketing, and information sharing, where quick access to digital content is desired. Users can engage with promotional offers, product information, or even social media links simply by scanning the code, streamlining the user experience.

Other applications mentioned in the question are not the primary functions of QR codes. While they can be used in various contexts, they do not serve the specific purpose of connecting users to web content as effectively as scanning does.