What ia an ERD. Define the RED related terms, including entities, attributes, cardinalities and relationships
In the field of database design, an Entity-Relationship Diagram (ERD) is a visual representation of the relationships between various entities in a database. ERDs provide a way to model complex databases and make it easier to understand the relationships between different data elements. Entities Entities are objects or concepts in a database that are important enough to be represented by a table. For example, in a university database, the entities might be students, courses, professors, and departments. Each entity has a unique identifier, known as a primary key, which is used to distinguish it from other entities. Attributes Attributes are characteristics or properties of an entity that are stored in the database. For example, a student entity might have attributes such as name, date of birth, and email address. Attributes can be further classified as either simple or composite, and as either single-valued or multi-valued. Cardinalities Cardinalities define the number of inst...

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