Flexibility in Implementation
There are several other reasons why you might want to use interfaces instead of class inheritance:
Interfaces are better suited to situations in which your applications require many possibly unrelated object types to provide certain functionality.
Interfaces are more flexible than base classes because you can define a single implementation that can implement multiple interfaces.
Interfaces are better in situations in which you do not have to inherit implementation from a base class.
Interfaces are useful when you cannot use class inheritance. For example, structures cannot inherit from classes, but they can implement interfaces.