Encapsulation of OOA

Encapsulation separates the interface of an abstraction from its implementation. By taking the above example i.e. of a car, we can now categorize them as:

Abstraction                Car

Interface                      pedals, Steering, controls

Implementation           Generally, you don't know

Encapsulation can also define data hiding, which compromises of separating the external aspects of an object, which are available to other objects.