What is Polymorphism and inheritance explain with example?

Polymorphism, is an object-oriented programming concept, which relates to the ability to create a variable, function or an object that has more than one form. This allows the object to invoke the correct instance of the variable, function or other object based upon the object type. The most common use of polymorphism in OOP occurs when a parent class reference is used to refer to a child class object.

Here are some links to examples:

C++: http://www.cplusplus.com/forum/beginner/10884/

Java

c#: http://msdn.Microsoft.com/en-us/library/ms173152.aspx

Python: http://en.wikipedia.org/wiki/Polymorphism_in_object-oriented_programming

Java: http://www.tutorialspoint.com/Java/Java_polymorphism.htm