A schema is an outline of the structure of a data record. A Verifiable Credential or VC Schema is a document used to guarantee the structure, and by extension the semantics, of the set of claims comprising a Verifiable Credential. Think of it like a presentation template for credentials. Why does it matter? In order for multiple parties to talk to each other, they need to agree on a common language and format. A shared VC schema template allows all parties to reference data in a known way.
Schemas are used by both humans and machines. Humans can view the representation of a VC schema and understand what type of data is required. Machines use Schemas to programmatically validate VCs and create user interfaces for humans to fill out VC forms. Each schema on Serto Schemas can be used according to one of two schema standards: JSON-LD context and JSON Schema JSON-LD contexts are JSON data that define data relationships and semantics, and can leverage property and entities types on schema repositories such as schema.org. For more details on using JSON-LD contexts in VCs, see the contexts section of the VC spec: https://www.w3.org/TR/vc-data-model/#contexts JSON Schemas are also JSON data, but define data structure, requirements, descriptions and other metadata, thereby supporting validation of VCs to ensure conformance. For more details on using JSON Schemas in VCs, see the credentialSchema field in the VC spec: https://www.w3.org/TR/vc-data-model/#data-schemas
Schemas hosted on Serto Schemas can be referenced by their URL and included in your VCs to identify them as instances of that schema.
Serto Schemas builds upon several widely-adopted internet standards, applying the benefits of both JSON-LD contexts and JSON Schema to Verified Credentials. Read more about these technologies: W3C Verified Credentials: https://www.w3.org/TR/vc-data-model/ JSON-LD contexts: https://w3c.github.io/json-ld-syntax/#the-context JSON Schema: https://json-schema.org