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Technical implementation · Entity & Knowledge Graph

Definition

An ontology is a formal representation of knowledge within a domain — defining the entities, concepts, properties, and relationships that exist within that domain and how they relate to each other. Schema.org is a practical ontology for web content; Wikidata uses an ontology to structure its knowledge base. Ontologies are the conceptual architecture that knowledge graphs are built on. When a brand implements schema.org markup, it is placing itself within a shared ontology that AI systems use to understand what the brand is and how it relates to other entities. Understanding ontology helps explain why using the correct schema.org type — and the correct properties for that type — matters more than creative improvisation with custom markup.

Schema.org

Entity type

Knowledge graph

Entity schema

Wikidata

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