Update README.md

Author: serhatyamann

README.md

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 # OOP_Object_Oriented_Programming
-Object Oriented Programming - C# .NET
+### Object-oriented programming (OOP) is the core ingredient of the .NET framework. OOP is so important that, before embarking on the road to .NET, you must understand its basic principles and terminology to write even a simple program. The fundamental idea behind OOP is to combine into a single unit both data and the methods that operate on that data; such units are called an object. All OOP languages provide mechanisms that help you implement the object-oriented model. They are encapsulation, inheritance, polymorphism and reusability. Let's now take a brief look at these concepts.
+
+* OOP's overview
+* Classes and Objects
+* Constructor and Destructor
+* Function Overloading
+* Encapsulation
+* Inheritance
+* Interface
+* Polymorphism