Entity-Relationship (ER) Model is based on the notion of real-world entities and relationships among them. While formulating real-world scenario into the database model, the ER Model creates entity set, relationship set, general attributes and constraints.
ER Model is best used for the conceptual design of a database.
ER Model is based on −
1. Entities and their attributes.
2. Relationships among entities.
The ER(Entity Relationship) model defines the conceptual view of a database. It works around real-world entities and the associations among them.
Entity-
An entity can be a real-world object, either animate or inanimate, that can be easily identifiable. For example, in a school database, students, teachers, classes, and courses offered can be considered as entities.
Entities are represented by means of rectangles. Rectangles are named with the entity set they represent.
