IN OOP encapsulation is a major

Class: Method: private : protected
IN OOP encapsulation is a major update in PHP5, we all know public is global, and difference between protected and private is distinguished.
Private	Protected
A private class can be accessed only locally. A derived class can't inherit private classes, therefore you may use same methods or properties as the base class.	It is similar to that of private, but can be accessed by an derived object.