Neo4j is a commercially provided graph database management system developed by Neo4j, Inc. The graph database is fundamentally different to the relational model found in relational database management systems (RDBMS). With Neo4j, each data record, or node, stores direct pointers to all the nodes it's connected to. The database is also designed to perform complex queries with complex connections orders of magnitude faster. Neo4j is ACID-compliant and suited for projects that requires complicated relationship structures.