图数据库也可称为面向/基于图的数据库，对应的英文是Graph database。图数据库的基本含义是以“图”这种数据结构存储和查询数据，不是存储图片的数据库。图数据库的基本存储单元为：节点、关系、属性。

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.

Most graph databases are NoSQL in nature and store their data in a key-value store or document-oriented database. In general terms, they can be considered to be key-value databases with the additional relationship concept added. Relationships allow the values in the store to be related to each other in a free form way, as opposed to traditional relational databases where the relationships are defined within the data itself. These relationships allow complex hierarchies to be quickly traversed, addressing one of the more common performance problems found in traditional key-value stores. Most graph databases also add the concept of tags or properties, which are essentially relationships lacking a pointer to another document.