Why use interfaces instead of abstract classes?
The key difference between abstract class and interface based inheritance is that concrete classes are bound to a single abstract class hierarchy, they are tightly coupled and cannot extend any other class. This makes it difficult to create general purpose component classes that can be re-used in different packages. Interface based inheritance does not create a binding to a specific class hierarchy, so concrete classes can inherit the type characteristics of several interfaces without limiting their scope for re-use. Concrete classes can implement multiple interfaces and extend an abstract class, but it is best to minimise class inheritance as far as possible to preserve lexibility. Actions: Follow-up or correct this answer. Submit a new question.
