interface vs abstract

interface.java

interface Example1{
    public void display1();
}
interface Example2 extends Example1{
}
class Example3 implements Example2{
   public void display1(){
      System.out.println("display1 method");
   }
}
class Demo{
   public static void main(String args[]){
      Example3 obj=new Example3();
      obj.display1();
   }
}