Az Erdе‘rе‘l Direct

: Defines the numerical relationship between entities, such as one-to-one , one-to-many , or many-to-many . Why ERDs are Useful

: They act as a blueprint for developers to build the actual physical database. AZ erdЕ‘rЕ‘l

: Adds more detail, defining attributes and keys but remaining independent of a specific database technology. : Defines the numerical relationship between entities, such

: Represented as diamonds or connecting lines, these show how entities interact (e.g., a Customer "places" an Order ). : Represented as diamonds or connecting lines, these

: Represented as ovals, these describe the specific characteristics of an entity (e.g., a Customer entity might have attributes like Name or Email ).

: They serve as high-level documentation of a system’s information architecture. Levels of Abstraction

An is a visual report used to design and model relational databases by illustrating how different "entities" (like people, objects, or concepts) relate to one another within a system. Core Components of an ERD