Abstract class vs. interface

abstract class IDareYa {
    abstract void speak();
}

public class InstantiateAbstract {
    public static void main(String[] args) {
        IDareYa InstancefromAbstractClass = new IDareYa() {
            void speak() {
                System.out.println("Hello World! from instance of Abstract Class using Java");
            }
        };
        InstancefromAbstractClass.speak();
    }
}