Question: what are the types of navigational database?
Answer: Relational DBMS (RDBMS) Example systems: Microsoft Access and MySQL. ... 
Document stores. Example systems: MongoDB. ... 
Key-value stores. Example systems: Redis. ... 
Search engines. Example systems: Elasticsearch. ... 
Wide column stores. ... 
Graph DBMS. ... 
Time series DBMS. ... 
Native XML DBMS.