Neo4j is a graph database: data is stored as nodes and relationships, so that highly connected data such as networks, dependencies or knowledge graphs can be queried directly. Organisations use it for connected-data applications and as a basis for GraphRAG, in which language models are supplied with data from a graph. Neo4j is available in two ways: self-managed, as the Graph Database with additional analytics and data-science components, and as a managed cloud service called Aura (AuraDB), which runs on AWS, Azure and Google Cloud.
Neo4j, Inc. is headquartered in San Mateo, California (US); the project began in Sweden in 2007, and part of its engineering remains there. The Community Edition is open source under GPLv3, while the Enterprise Edition is closed source under a commercial licence. According to the Aura documentation, European regions are available, including Frankfurt, Paris and Ireland on AWS and several European regions on Azure and Google Cloud. Because the vendor is a US company, the service falls under US jurisdiction even when hosted in the EU.