Key Concepts in ERD:
- Entities: Objects or concepts, represented as rectangles or ovals, that have a distinct existence in the system.
- Relationships: Lines connecting entities that define how the entities are related.
- Cardinality: Specifies how many instances of one entity can be associated with instances of another entity (one-to-one, one-to-many, or many-to-many).
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- You could just make a note about the relationship. Not all relationships are about how many.
- Attributes: Details about the entities (e.g., a person has a name, address, etc.).
This technique is useful for designing databases or analyzing how different components of a system are related to each other.