A File is a bunch of bytes stored on some storage device like magnetic disk or tape etc. Most of the application programs process large volume of data which is permanently stored in files. We can write programs that can read data from file(s) and write data to file(s).
Polymorphism is made from two words POLY+MORPHISM which means more the one form. In C++ polymorphism is implemented by overloading a function or an operator. In Function Overloading a single function name is used to perform different tasks.
In C++, a class only creates a data type and the objects of a class are created and initialized as separate. A constructor (having the same name as that of a CLASS) is a member function which is automatically used to initialize the objects of the CLASS type with legal initial values.
