Object Orientated Programming

when object oriented programming was not invented then programmers used procedural programming methods

i.e. whole program was just one part and the sequential flow of the program was there

the programs were not so much readable and if there was some big problem to solve then programmers needed to code in a hectic way as no grouping facilities were there.

In object oriented programming, we can form groups of code for specific purpose, those are called as methods

and we can create the objects those are instances of the classes we have created. These objects can call the methods of respective classes

also

the object oriented programming concepts allow us to use some features like data encapsulation which allows us to protect our data from outer methods, concept of polymorphism which allows us to use same method name for different purposes and many features

If you want some more information about OOP then visitthis link

An object is actually a discrete bundle of functions and procedures, all relating to a particular real-world concept such as a bank account holder or hockey player in a computer game. Other pieces of software can access the object only by calling its functions and procedures that have been allowed to be called by outsiders. A large number of software engineers agree that isolating objects in this way makes their software easier to manage and keep track of. However, a not-insignificant number of engineers feel the reverse may be true: that software becomes more complex to maintain and document, or even to engineer from the start. The conditions under which OOP prevails over alternative techniques (and vice-versa) often remain unstated by either party, however, making rational discussion of the topic difficult, and often leading to "religious wars" over the matter.

Object-oriented programming (OOP) is a programming paradigm based on the concept of "objects", which may contain data, in the form of fields, often known as attributes; and code, in the form of procedures, often known as methods. A feature of objects is that an object's procedures can access and often modify the data fields of the object with which they are associated (objects have a notion of "this" or "self"). In OOP, computer programs are designed by making them out of objects that interact with one another.^[1][2] There is significant diversity of OOP languages, but the most popular ones are class-based, meaning that objects are instances of classes, which typically also determine their type.

Many of the most widely used programming languages (such as C++, Object Pascal, Java, Python etc.) are multi-paradigm programming languages that support object-oriented programming to a greater or lesser degree, typically in combination with imperative, procedural programming. Significant object-oriented languages include Java, C++, C#, Python, PHP, JavaScript, Ruby, Perl, Object Pascal, Objective-C,Dart, Swift, Scala, Common Lisp, and Smalltalk.