Entity-Relationship Model is the diagrammatical representation of a database structure which is called an ER diagram. The ER diagram is considered a blueprint of a database which has mainly two components i.e. relationship set and entity set. The ER diagram is used to represent the relationship exists among the entity set. The entity set is considered as a group of entities of similar type which contains attributes. According to the database system management system the entity is considered as a table and attributes are columns of a table. So the ER diagram shows the relationship among tables in the database. The entity is considered a real-world object which is stored physically in the database. The entities have attributes that help to uniquely identify the entity. The entity set can be considered as a collection of similar types of entities.