What is an ERD. Define the RED related terms, including entities, attributes, cardinalities and relationships

Entity Relationship Diagram

 An Entity Relationship Diagram (ERD) is a visual representation of entities and their relationships with each other. It is a graphical representation of data and the relationships between different entities in a database. An ERD typically consists of entities, attributes, cardinalities, and relationships.

Entities: An entity is a real-world object or concept used to model data in a database. Examples of entities include customers, products, orders, and employees.

Attributes: Attributes are the characteristics of an entity. Examples of attributes include name, age, address, and gender. 

Cardinalities: Cardinalities are the relationships between entities. There are three types of cardinalities: one-to-one, one-to-many, and many-to-many. 

Relationships: Relationships are the connections between entities. Examples of relationships include “customer has an order” and “employee works at a department”. 

 Reference: 

Kumar, A., 2020. What Is An ERD? [online] Available at: <https://www.guru99.com/erd-tutorial.html> [Accessed 12 October 2020].