Defines the numerical context of relationships, such as One-to-One (1:1), One-to-Many (1:N), or Many-to-Many (M:N). The Three Levels of Data Modelling
Defines the high-level business scope and key concepts, focusing on business vocabulary rather than technical detail.
Countable objects, concepts, or events, such as Customer , Product , or Order .
The associations between entities, such as a Customer "places" an Order .
Modelling Business Information using Entity-Relationship (ER) diagrams is a foundational technique for defining the structure, relationships, and rules of data within an organization . It acts as a bridge between business requirements and technical database design, enabling stakeholders to visualize the "things" (entities) a business cares about and how they interact. Core Components of ER Modelling
