Az Erdе‘rе‘l -
: They act as a blueprint for developers to build the actual physical database.
: The most detailed version, showing actual table structures, data types, and constraints for a specific database management system. AZ erdЕ‘rЕ‘l
: A high-level view showing major entities and their relationships without technical details. : They act as a blueprint for developers
: Analysts use them to identify logic errors in existing database structures. showing actual table structures
: Represented as rectangles, these are the "nouns" of the system, such as Customer , Order , or Product .
: Adds more detail, defining attributes and keys but remaining independent of a specific database technology.