A traditional barcode encodes only a number. A GS1 Digital Link encodes a resolvable URL of the shape `https://id.example.com/01/<GTIN>/21/<serial>`, so the same printed QR can serve a human-readable page in a browser and a machine-readable JSON-LD passport to a system that asks for it (via HTTP content negotiation).
For a Digital Product Passport this matters because one carrier on the physical product has to serve many audiences — consumers, recyclers, market-surveillance authorities — each needing different data. GS1 Digital Link is how one QR does that without printing several codes.
Frequently asked
Is GS1 Digital Link the same as a normal QR code?
The QR symbol is the same; what differs is what's encoded inside. A GS1 Digital Link QR encodes a structured, resolvable web URL rather than a bare number, which is what lets one code serve a passport, a consumer page and a service endpoint.
Does the EU Digital Product Passport require GS1 Digital Link?
No. ESPR requires a data carrier and a unique identifier that follow the standards; EN 18219 accepts several identifier schemes, GS1 Digital Link among them. TracePass uses GS1 Digital Link by default and also supports the other EN 18219 schemes.
Authoritative source: www.gs1.org/standards/gs1-digital-link