Interfaces - implements or derives from
An interface is a class that lacks implementation. The only thing it contains are definitions of events, indexers, methods and/or properties. The reason interfaces only provide definitions is because they are inherited by classes and structs, which must provide an implementation for each interface member defined. Since classes in c# can only be derived from one other class ( in c++ it is possible to derive from many) interfaces are used for multiple inheritance. Like abstract classes you cannot create an instance of an interface on derive from it.
/infod/jeff/classSource/class5/interface.cs -source /infod/jeff/classSource/class5/interface2.cs -source Phone interface example phoneIFace.cs -source Multiple interface inheritance - inherits IPhone, Cell, POTS /infod/jeff/classSource/class5/phoneIFacePOTS.cs -source