From a number to a web address
GS1 Digital Link is the GS1 standard that expresses a product identifier as a web URL. Instead of a barcode that only holds a number, a GS1 Digital Link QR code holds a URI such as id.example.com/01/09506000134352, where 01 introduces the GTIN. The same URI can also carry a batch, introduced by 10, or a serial, introduced by 21.
One QR code, many purposes
Because it is a normal web address, one GS1 Digital Link can serve retail checkout, a consumer Digital Product Passport, care and repair information, authentication and a persistent Digital Twin. This is why GS1 describes the transition to 2D codes at retail point of sale, often called Sunrise 2027, as the moment a single code can do all of this.
The role of the resolver
A resolver is the service that receives a GS1 Digital Link request and routes it, by declared link type, to the right destination: the passport, the product page, a certificate or an API. The resolver behaviour is standardised so that different systems interpret the same link consistently.
Model, batch and item level
GS1 Digital Link expresses identity at different granularities. A GTIN alone identifies the product model. Adding a batch identifies a production lot. Adding a serial identifies one individual unit. A passport or twin can therefore attach data at the level the regulation and the use case require.