What is the object instantiated from an Interface-Collection of common programming errors

As already stated in other answers, Person is an interface so can’t be instantiated. Therefore it is useful to include the arguments in the constructor of the implementing class since the latter’s setters will not be directly accessible from a Person reference

public Student(int id, String name) {
    this.id = id;
    this.name = name;
}

so as to initialize

Person s = new Student(1, "Jon Smith");