How does polymorphism function within OOP?

Polymorphism in object-oriented programming (OOP) plays a crucial role in enabling objects to be treated as instances of their parent class. This aspect of polymorphism ensures that a single interface can be used to represent different underlying forms (data types). Essentially, it allows methods to do different things based on the object that it is acting upon.

For example, if there is a method defined in a parent class and overridden in one or more child classes, a reference of the parent class can invoke the method, executing the version that corresponds to the actual object's class. This means that even if the variables are of the parent class type, the program will call the appropriate child class method, facilitating dynamic method resolution at runtime.

This characteristic enhances flexibility and scalability in code, allowing for easier maintenance and the ability to introduce new classes with minimal changes in the existing codebase. Polymorphism is one of the key principles of OOP, promoting code reuse and modular programming.