1) Hierarchical Database
A hierarchical database is a design that uses a one-to-many relationship for data elements. Hierarchical database models use a tree structure that links a number of disparate elements to one “owner,” or “parent,” primary record
The network database model allows each record to have multiple parent and multiple child records, which, when visualized, form a web-like structure of networked records. In a hierarchical model, data members can only have a single parent record but can have many child records.