What is Polymorphism: The word polymorphism means having many forms. In programming, polymorphism means the same function name (but different signatures) being used for different types.

Polymorphism is a concept in object-oriented programming (OOP) that refers to the ability of an object to take on multiple forms. In Python, polymorphism is achieved through method overriding and method overloading.

Method overriding is a process where a subclass provides a different implementation of a method that is already defined in its parent class. This allows objects of the subclass to have behavior that is different from the parent class, but still have the same interface. For example, if we have a parent class Animal with a method called speak(), we can create a subclass called Dog that overrides the speak() method to make a barking sound.

Method overloading, on the other hand, is the process of defining multiple methods with the same name but different parameters. When a method is called, the correct method to execute is chosen based on the arguments passed in. This allows us to use the same method name to perform different actions depending on the inputs. However, Python does not support method overloading natively, so we have to use tricks like default arguments or variable arguments to achieve this effect.

Polymorphism is useful in Python because it allows for code reusability and flexibility, since objects can be treated in a general way regardless of their specific implementation.