A database that stores data as nodes connected by relationships, so queries can follow those connections directly.
Graph Databases (like Neo4j) map the physical and conceptual relationships within an enterprise. When integrated into an AI architecture, they allow models to execute complex, multi-hop reasoning (e.g., 'Find all employees who worked on Project X and possess Security Clearance Y'), which is impractical with standard vector search alone.
See also Data Mobilization, Data Lakehouse and Vector Database.