the IMyInterface interface declares a method called MyMethod and provides a default implementation that writes "Default implementation" to the console. Classes that implement the IMyInterface interface can use this default implementation if they don't provide their own implementation for the method. 

the MyClass class implements the IMyInterface interface but doesn't provide its own implementation for the MyMethod method. When an instance of MyClass calls MyMethod(), it uses the default implementation provided by the interface.

Note that default interface methods can also be overridden by classes that implement the interface, just like regular interface methods.