What does polymorphism allow in programming?

Polymorphism in programming enables objects of different classes to be treated as objects of a common superclass. This is particularly valuable as it allows for a unified interface to be implemented across various class types. By having a common interface, different classes can provide their own specific implementations of the same method, leading to enhanced flexibility and reusability in code.

For example, if you have a superclass called "Animal" with a method "makeSound," different subclasses like "Dog" and "Cat" can implement this method in distinct ways—dogs bark while cats meow. When you use polymorphism, you can create a list of "Animal" types that can hold both "Dog" and "Cat" objects. Thus, you can call "makeSound" on any "Animal" in the list without needing to know the specific class of the object at runtime; the correct method for each class will be executed.

This demonstrates how polymorphism streamlines coding and enhances modular design, allowing developers to work with different data types and functions without being bogged down by the specifics of each individual type.