oops concepts are Encapsulation, inheritance, abstractio 
and polymorphism.

Encapsulation: Buildingup of the data and methods as a 
single unit is called encapsulation. It isolates the 
members of one class from the members of another class, so 
we can declare same variable in both the classes.

best example for encapsulation is: A Class


Inheritance: Producing the new classes from already 
existing class is called inheritance. The newly produced 
class contains the features of old class and it has its own 
features.

the use of inheritance is reusability. 

Abstraction: Hiding unnecessary data from the user is 
called Abstraction. 

Polymorphism: Poly means many. Morphism means forms.
If same object perfrom different tasks is called 
polymorphism.

abstartcion
inheritence
polymorhism
encapsulation