RDF

RDF (Resource Description Framework) is a W3C standard framework for representing information about resources as a graph of subject-predicate-object triples. Each triple states a single fact, such as (Alice, worksFor, AcmeCorp), and collections of triples form a knowledge graph. Resources are identified by URIs, allowing global, unambiguous identification of entities and relationships.

RDF provides a formal, standardized way to publish and link data on the web (Linked Data). It supports schema definition through RDFS (RDF Schema) and richer ontological reasoning through OWL (Web Ontology Language). RDF data is queried using SPARQL and can be serialized in various formats including Turtle, JSON-LD, and RDF/XML.

While property graph databases like Neo4j are more common in industry RAG+KG applications due to their flexibility and performance, RDF remains the standard for semantic web applications, open data initiatives, and domains requiring formal reasoning (biomedical, government, library science). Understanding RDF is valuable for working with public knowledge bases like Wikidata and for applications requiring interoperability across organizations.