RDF

RDF (Resource Description Framework) is a way of describing anything, a person, a document, a fact, as a simple three-part statement: subject, predicate, object. "Alice knows Bob" becomes a triple; so does "this photo was taken on this date" or "this Pod belongs to this WebID." Link enough triples together and you get a graph of facts that different systems, built by different people, can query and combine without agreeing on a shared database schema first, which is the actual point: RDF is the data model underneath Tim Berners-Lee's original Semantic Web vision, and it's what Solid uses to represent everything stored in a Pod.

RDF is a W3C Recommendation, first specified in 1999 and revised as RDF 1.1 in 2014.

Where Solidus stands

Solidus's own Pod backend stores data in Postgres, in conventional relational/JSON form, not as RDF triples. That's a real gap relative to Solid conformance, and we won't describe it otherwise. There is one honest adjacency worth knowing: Solidus's Verifiable Credentials are serialized using JSON-LD, and JSON-LD is itself a way of writing RDF, so RDF concepts do reach into Solidus's credential layer, just not into the Pod's storage layer.

Proof

Read the spec at w3.org/TR/rdf11-concepts/. To see RDF for yourself, take any RDF or Turtle snippet and paste it into a public RDF validator, it either parses or it doesn't. We don't have a Solidus-run RDF storage proof to offer, because our storage layer isn't RDF.