Database Model

A Database model defines the logical design of data. The model describes the relationships between different parts of the data. Historically, in database design, three models are commonly used. They are,
  • Hierarchical Model
  • Network Model
  • Relational Model

Hierarchical Model

In this model each entity has only one parent but can have several children . At the top of hierarchy there is only one entity which is called Root.

Network Model

In the network model, entities are organised in a graph,in which some entities can be accessed through several path.

Relational Model

In this model, data is organised in two-dimesional tables called relations. The tables or relation are related to each other.