This principle generalizes the properties and methods of classes in such a way that the implementations are hidden from outside the class.

The principle you're referring to is known as Encapsulation. Encapsulation is one of the four fundamental principles of Object-Oriented Programming (OOP). Here's a step-by-step explanation:

1. Encapsulation is the process of hiding the internal details of how an object works.

2. In OOP, a 'class' is like a blueprint for creating objects. A class can contain properties (attributes) and methods (functions).

3. When we encapsulate a class, we're making its properties and methods private. This means they can't be accessed directly from outside the class. Instead, they must be accessed through public methods within the class.

4. These public methods are known as 'getters' and 'setters'. A 'getter' returns the value of a private property, and a 'setter' changes the value of a private property.

5. By using encapsulation, we can control how a class's properties are accessed and modified. This helps to prevent errors and keep the data in a consistent state.

6. Encapsulation also makes a class easier to use and understand, because you don't need to know how it works internally in order to use it. You just need to know what methods it provides.

7. In summary, encapsulation is about hiding the implementation details of a class, and providing a simple interface for using the class.