(i) Re-usability
(ii) Redundancy
(iii) Easy Maintenance
(iv) Security.

Inheritance is the technique of building new classes (derived class) from an existing Class (base class). The most important advantage of inheritance is code reusability.

Modularity is designing a system that is divided into a set of functional units (named modules) that can be composed into a larger application.

Encapsulation is the most striking feature of a class The data is not accessible to the outside world, and only those functions which are wrapped in the class can access it. These functions provide the interface between the object's data and the program.

Encapsulation is about binding the data variables and functions together in class. It can also be called data binding.

Main Features of Object Oriented Programming:
(i) Data Abstraction
(ii) Encapsulation
(iii) Modularity
(iv) Inheritance
(v) Polymorphism.

An identifiable entity with some characteristics and behaviour is called object

It can also be defined as a template or blueprint representing a group objects that share common properties and relationship.

The object-oriented paradigm allows us to organize software as a collection of objects that consist of both data and behaviour.

Object-Oriented Programming (OOP) is the term used to describe a programming approach based on classes and objects.

Size: Object Oriented Programs are much larger than other programs.
Effort: Object Oriented Programs require a lot of work to create.
Speed: Object Oriented Programs are slower than other programs, because of their size.

Abstraction means giving only essential things and hiding unnecessary details. Encapsulation is the binding of data members and methods together in a capsule to avoid accidental changes to data from external users. i.e., encapsulation is the bundling of related algorithms and data.

Polymorphism is the ability of a message or function to be displayed in more than one form.

Class	Object
Class is a blue print or template from which objects are created.	Object is an instance of a class.
Class doesn't allocate memory when it is created.	Objects allocate memory when it is created.
Class is a logical entity.	Object is a physical entity.

Modular programming	Procedural programming
Emphasis on algorithm rather than data.	Programs are organized in the form of subroutines or sub programs.
Programs are divided into individual modules.	All data items are global.
Each modules are independent of each other and have their own local data.	Suitable for small sized software application.
Modules can work with its own data as well as with the data passed to it.	Difficult to maintain and enhance the program code as any change in data type needs to be propagated to all subroutines that use the same data type.