Abstraction:* Abstraction is one of the OOP's feature, Different levels of hiding the PE's (data, instructions) is called abstraction which contains private, protected, public and global keywords
* By default Data Members should be hidden and instructions should be visible.
Abstract:* Abstract class is a class which contains method prototypes.
* By default class is final, it is not possible to inherit final class.
* To inherit class, it should be of virtual or abstract class type.