ANSWER: allows normal method declaration within
Abstraction is the process of hiding implementation details and showing only functionality to the user. Classes that are declared with keyword abstract are called abstract classes. It cannot have any instances. It can carry normal functions declaration and definition along with abstract functions though the abstract methods(functions) cannot be defined inside the abstract class.For defining abstract methods subclasses are needed. Any class that extends the abstract class must implement all abstract methods declared by the super class.