What is the role of an interface in C#?

In C#, an interface is a type that defines a set of methods, properties, and events, providing a convention for defining shared behavior between different classes.

The functions of interfaces include:

1. Definition of standards: An interface defines a set of methods, properties, and events standards, which classes can implement to meet these standards. With interfaces, it is possible to define which methods and properties should be implemented and how to handle events.
2. Achieving polymorphism: Interfaces allow classes to achieve polymorphism by implementing one or more interfaces, meaning an object can be viewed as different types and operated on based on the desired type.
3. Provide a consistent interface: The interface can offer consistency, allowing multiple different classes to implement the same interface with the same methods and property names. This can make the code easier to understand and maintain.
4. Achieving loose coupling: By using interfaces, classes can rely on interfaces rather than specific implementations to achieve loose coupling. This makes code easier to extend and modify, as classes can change behavior by implementing different interfaces.

In general, interfaces provide a way to define shared behaviors, making code more scalable, maintainable, and flexible. They are an important tool in C# for implementing abstraction and polymorphism.