Encapsulation has two faces; data abstraction and information hiding. Data abstraction is a type seen from the outside. Information hiding is a type seen from the inside.

Sometime encapsulation is used to mean information hiding only but I think the definition I gave is better because if you encapsulate something you get both an inside and an outside right.

* Abstraction focuses on the outside view of an object (i.e. the interface)



* Encapsulation (information hiding ) prevents clients from seeing its inside view, where the behavior of the abstraction is implemented