In computer science and information science, a knowledge graph is a knowledge base that uses a graph-structured data model or topology to integrate data.^[1][2] Knowledge graphs are often used to store interlinked descriptions of entities — objects, events, situations or abstract concepts — while also encoding the semantics underlying the terminology.

A knowledge graph represents data as a network of entities and their semantic relationships. The term was popularized by the introduction of the Google Knowledge Graph in 2012, and has been adopted by many open knowledge graph projects since then, including Wikidata.^[3]

Besides applying the graph-based data models, such as semantic networks, to data, knowledge graphs often adopt ontologies as their semantic layer and use graph databases as their storage layer. Some implementations are used by machine learning systems as sources of structured training data.^[4]