RDF

RDF, the Resource Description Framework, is a W3C standard for representing information as a graph of subject-predicate-object statements called triples. Instead of rows and columns, RDF describes resources by URIs and links them together, so data from different sources can be merged into a single, queryable graph. It is the foundational data model beneath linked data and the semantic web.

• Triples as the atom - Every fact is a subject → predicate → object statement, and a set of triples forms a graph.
• URIs everywhere - Resources and relationships are named with URIs, so meaning is global and datasets can interconnect.
• Multiple serializations - The same graph can be written as Turtle, N-Triples, RDF/XML, or JSON-LD depending on the consumer.
• Queryable with SPARQL - RDF graphs are searched and joined with the SPARQL query language across distributed sources.

In the API world, RDF shows up wherever data needs to be self-describing and mergeable across boundaries — government open-data portals, scientific and cultural-heritage datasets, and knowledge graphs that back search and reasoning. Its most API-friendly serialization, JSON-LD, carries RDF semantics inside ordinary JSON, which is how much of the linked-data model actually reaches modern APIs. As agents increasingly need machine-readable, unambiguous meaning rather than just structure, RDF’s decades-old bet on globally-identified, linkable facts is worth understanding even where teams adopt lighter-weight approaches.