Method overriding in Python occurs when a subclass provides a specific implementation of a method that is already defined in its parent class. This allows a subclass to customize or extend the behavior of an inherited method without changing the parent class. To override a method, the subclass defines a method with the same name and parameters as the one in the parent class. When the method is called on an instance of the subclass, Python executes the overridden version instead of the parent class’s method. The super() function can be used within the subclass method to call the parent’s version if needed, allowing for partial modification rather than a complete replacement. Method overriding is a key feature of polymorphism, enabling different behaviors for the same method name across different classes, making object-oriented programming more flexible and extensible.