A knowledge graph is a formal, graph-based model for representing knowledge, consisting of entities (nodes) and their semantic relations (edges).
It is often based on standards such as RDF or Property Graphs and uses ontologies to define classes, properties, and rules.
Knowledge graphs enable linking heterogeneous data sources and performing logical inference processes to increase knowledge.
Through SPARQL queries, complex knowledge can be efficiently extracted and utilized, for example in knowledge integration, data fusion, and AI applications.
Definition:
“A knowledge graph is a structured graph that represents entities and their relationships to make knowledge machine-readable and processable.”
Source:
Hogan, A., Blomqvist, E., Cochez, M., D'amato, C., De Melo, G., Gutierrez, C., ... & Zimmermann, A. (2021). Knowledge Graphs. ACM Computing Surveys (CSUR), 54(4), 1-37.