An Interface At first, interfaces came into focus because there was no multiple inheritance supported by C#, meaning you could not inherit from multiple classes, but you could implement multiple interfaces. The interfaces are grouping of object in terms of behavior. An interface contains only signatures. There is no implementation, only the signatures of the functionality the interface provides. An interface can contain signatures of methods, properties, indexers & events. Interface doesn't do anything like classes and abstract classes, it just defines what the class will perform if some class inherits it. An interface can also be inherited from another interface. If we take an example of USB (Universal Serial Bus), it's an interface which has signature of Connection functionality. The USB interface only knows I have to connect with Desktop Computer or laptop or anything, but it does not know what implementation will come to connection. It may be Pen d