In computing, a graph database is a database that uses graph structures for semantic queries with nodes, edges and properties to represent and store data. A key concept of the system is the graph (or edge or relationship), which directly relates data items in the store. This contrasts with conventional relational databases, where links between data are ad hocand based on the data itself, and related items are gathered by searching for this data within the store. Graph databases are designed to allow simple and rapid retrieval of complex hierarchical structures, whereas a relational database would use a complex query to achieve the same end, generally with far less performance (from wikipedia).
Neo4j is a highly scalable native graph database that leverages data relationships as first-class entities, helping enterprises build intelligent applications to meet today’s evolving data challenges.