What are the Different Database Models ?

Database model defines the logical design of data. Database model describes the relation between different parts of data.

There are Four Database models:

    1. Hierarchical Model
    2. Network Model
    3. Relational Model
    4. Entity-Relationship Model

1. Hierarchic Database Model

This is one of the oldest type of database  models. In this model data is represented in the form of records. Each record  has multiple fields. All records are arranged in database as tree like structure. 

The relationship between the records is called parent child relationship in  which any child record relates to only a single parent type record. 

2. Network Database Model

It replaced hierarchical network database model due  to some limitations on the model. Suppose, if an employee relates to two  departments, then the hierarchical database model cannot able to arrange  records in proper place.

So network, database model was emerged to arranged  non-hierarchical database. The structure of database is more like graph rather  than tree structure. 

3. Relational Database Model

In this model, the data is organized into tables  which contain multiple rows ad columns. These tables are called relations. A  row in a table represents a relationship among a set of values.

Since a table is  a collection of such relationships, it is generally referred to the mathematical  term relation, from which the relational database model derives its name. 

4. Entity-Relationship Database Model

This model is based on perception of a  real world that contains a collection of basic objects, called entities and of  relationship among these objects and characteristics of an entity. It shows  relationship between different entities.