A knowledge graph is a fabric of concepts, classes, properties, relationships and entities. It uses knowledge representation formalisms as RDF, RDF-Schema and OWL. Knowledge graphs typically cover multiple domains, various levels of granularity, data from multiple sources, various degrees of structure. It functions as background knowledge for various applications (e.g. question answering, data integration and machine learning). (Source: Sören Auer) Knowledge graphs are crucial for PoolParty's functions that represent and store data and make them available in other applications effectively this way.