Computersight -

Object Oriented Programming, also known as OOP, is a way of think about software based on real world abstraction. OOP foundation is the identification and organization of concepts belonging to the application domain, instead of the final representation of these concepts using a programming language.

In OOP software is organized as a objects collection. These objects contain data structures and their behaviour. In contrast, conventional programming is implemented in a way that data structures and behaviour have a weak relation.

Key Concepts

Class. A class describes a group of objects with common properties and functionalities. Each individual object is called an instance of the class.

Object. An object is a concept, abstraction or thing that has sense in a specific context, has well-defined boundaries, and also has a meaning in the problem to solve.

Polymorphism.  The same method can have different behaviours in different classes.

Inheritance. The capability of acquire attributes and methods from other classes, using a hierarchical relation between these classes, where an initial class called superclass is defined, and successive refining produce subclasses which inherit all the properties and methods of   the superclass.

Encapsulation. Also known as information hiding is the separation of the external aspects of the object and the internal details. External aspects can be accessed by the external world, and internal details remain hidden to the rest of the objects.

Abstraction. To define what an object is and what it should do, instead of think about how it should be implemented.