In computing, a database is an organized collection of data stored and accessed electronically.

 Type Explanation 
Document DatabaseA document-oriented database is designed for storing, retrieving, and managing document-oriented, or semi structured, information. Document-oriented databases are one of the main categories of NoSQL databases.
Graph Databaseuses graph structures with nodes, edges, and properties to represent and store information.
Relational DatabaseRelational tables contain data that are always linked bidirectionally via shared keys, aka an undirected graph.

See also