In realtime If we want to provide some of the features to lower developers then we will for abstract class and If we want to provide complete features to lower developers then we will go for Interface
Depends on the design consideration. If one wants the design to be flexible then go for the interface else abstract class. The abstract class can contain default implementation which is inherited by the subclasses by default. If you are looking for performance then abstract class is the best choice
Abstract class means partial implementation which means he cannot directly use properties of this class i.e he has to inherit it and use the class and also allowed to provide extra properties. One real time use of abstract class is it can be used as a Adapter class.
Interfaces are open for implementation, to use interfaces he has to provide implementaion to all methods. i.e interfaces are just specification which states what to do not how they are done.
