When someone scans a website QR code, the phone's camera reads the link inside it, and one tap opens the page in the default browser. With a saved QR Cake code, that link is a short QR Cake address that forwards to whatever destination you have set. On the free plan a brief ad page shows first; paid plans go straight to your page.
QR Cake also makes static codes. Download a website QR code without saving it and your URL is written straight into the pattern: scans go directly to your site with no QR Cake page in between, but the code can never be changed or tracked. Save it to your account instead and it becomes dynamic, so you can change the destination from your dashboard at any time, for example to move flyers already in circulation from an expired offer to a live one.
Choose static only for an address that will never change and that you'll never need to measure, like your homepage on a business card. Choose dynamic for anything printed in quantity or tied to a menu, price, event, or campaign, where a moved page would leave a dead code in circulation. For several links on one screen, a Link list QR code fits better.