What is the difference between polymorphism and overloading in C#?

Polymorphism and overloading are two important concepts in object-oriented programming, both serving as ways to achieve polymorphism, but differing in their specific implementation and application.

1. Polymorphism: Polymorphism refers to an object exhibiting different behaviors in different situations. In object-oriented programming, polymorphism can be achieved through inheritance and interface implementation. In C#, polymorphism is typically implemented through method overriding. When a parent class reference points to a child class object, calling the same method will result in different behaviors based on the actual type of the object.
2. Overloading: Overloading refers to the ability to define multiple methods with the same name but different parameter lists within the same class. In C#, method overloading can be achieved by changing the number, type, or order of parameters. The compiler determines which method to call based on the method’s parameter list. Overloading methods are done within the same class, unlike polymorphism which is done between parent and child classes.

Therefore, polymorphism is achieved by inheritance and overriding to exhibit different behaviors when different objects call the same method, while overloading is defining multiple methods with the same name in the same class to differentiate calls based on different parameter lists.