what is main objective of developing the concept of object oriented programming

Answer 1

We code to make computers do stuff, but writing code is a human activity. As Vlad said, the idea behind OOP is to write code that kind of models the real world that is easy for humans to deal with, and has been very successful in large applications

Answer 2

Order. Large programs in non-OOP languages, like C, are inherently chaotic and hard to understand. Meanwhile, in object-oriented language each element is an object (like in real life), and has a number of attributes and a number of things it can do (again like in real life).

This simplifies everything. Especially in debugging. Say you're debugging a game, and an enemy behaves in an unexpected way, you know where to look: that enemy's class. Moreover if he did so while moving, you check his move method. If all enemies are acting like that, you check the class from which all specific enemies inherit. You get the point.