Polymorphism

In object-oriented programming, Polymorphism means the ability to use same named method (function) or operator in different ways.

Also,

The ability that allows an operator or function to respond differently when supplied with arguments that are objects of different types is called polymorphism.

 In other words, polymorphism allows you define one interface and have multiple implementations. 

This technique of OOP is achieved in different ways such as method overriding, method overloading, and operator overloading.

Example:

Method overloading. (define two or more methods of same name in a class with different number of arguments).

Java Code: 

class Overload
{
    void demo (int a)
    {
       System.out.println (a);
    }
    int demo (int a, int b)
    {
       return a*b;
    }
}

class MethodOverloading
{
    public static void main (String args [])
    {
        Overload Obj = new Overload();
        Obj.demo(10);
        int result=Obj.demo(10, 20);
     
        System.out.println(result);
    }
}

Polymorphism is the process of passing through different bodily forms in the course of an organism's development, as in a frog or butterfly.