OOP has become a fundamental part of software development. We can’t develop software for mobile unless we understand the object-oriented approach. OOP is the object oriented programming approach to any programming language. By using these features we can easily reuse our program or part of our program. OOP provides us a power to do programming in a very effective manner. If we have written this kind of software, we are probably used to breaking down large problems into sub-problems and solving them in separate units of code. Or we may have experience with functional programming, which treats elements of code as precise mathematical functions, and prevents them from affecting other elements.