: They serve as high-level documentation of a system’s information architecture. Levels of Abstraction
: Defines the numerical relationship between entities, such as one-to-one , one-to-many , or many-to-many . Why ERDs are Useful AZ erdЕ‘rЕ‘l
: Represented as diamonds or connecting lines, these show how entities interact (e.g., a Customer "places" an Order ). : They serve as high-level documentation of a
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 such as one-to-one
: They act as a blueprint for developers to build the actual physical database.
: Adds more detail, defining attributes and keys but remaining independent of a specific database technology.