Encapsulation

With the use of objects; application and system software no longer know about the precise format of the data structure.

That knowledge is contained within the object itself and is not visible outside the object.

Because it is not visible, any change to the data structure have no impact on application or system software.

The software is independent of the underlying structure.

This characteristic of hiding the internal details is called encapsulation.

Inside the AS/400, Frank G. Soltis