What Is a Knowledge Graph?

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Knowledge Graphs Explainer

A knowledge graph represents information as entities connected by relationships. A node might represent a person, place, organization, event, or concept, while a labeled edge states how two nodes are related. Properties attach dates, identifiers, measurements, or other attributes.

Many graphs express facts as triples: subject, predicate, and object. Standards such as RDF give identifiers and relationships a shared structure, while schemas or ontologies define classes, allowed relationships, and meaning. Graph query languages retrieve patterns spanning several connections.

Knowledge graphs can integrate records from different systems, support search and recommendations, provide context for question answering, and make relationships easier to inspect. They are often combined with embeddings or language models for retrieval and reasoning.

A graph is only as trustworthy as its sources and modeling choices. Entities can be duplicated, relationships may be uncertain or time-dependent, and an ontology can omit important perspectives. Useful systems retain provenance, confidence, versioning, access rules, and a process for corrections.

A knowledge graph represents entities and their relationships as connected nodes and labeled edges that software can query and combine.

Key terms include entity, relation, node, edge, triple, identifier, ontology, schema, query and provenance.

A triple links a subject to an object through a named predicate. Shared identifiers let records from different sources refer to the same entity.

Schemas and ontologies describe classes and constraints, while graph queries match paths and relationship patterns that would require many joins in a table design.

A graph can encode disputed, outdated, or incorrectly merged facts with great precision, so every important assertion needs source and time context.

Entity resolution, provenance, confidence, permissions, versioning, and human correction are essential when the graph informs consequential decisions.

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