The document discusses database abstraction and interface design. It states that a driver only needs to know an engine's interface, not its internal workings. The interface hides the implementation details and provides a simplified view. Encapsulation is achieved through separating an object's interface from its implementation.

1. Conception Avancée de Base de Données Abstraction : Interface

2. Design By and For Interfaces Implementation Interface A driver doesn't care of engine's internal working. He only knows the interface

3. Design By and For Interfaces Implementation Interface A driver doesn't care of engine's internal working. He only knows the interface

4. Interface and implementation Source : OBJECT-ORIENTED PROGRAMMING AND THE OBJECTIVE-C LANGUAGE NeXT DEVELOPER’S LIBRARY

5. Encapsulation Modèle = vue simplifiée interface