Question

If we have this:

class Car
{
    public void mCar()
    {

    }

}

class Audi : Car
{
    public void mAudi()
    {

    }
}

and in some other class, we have:

Car x = new Audi();

then we only have access to mCar(), but not to mAudi().
My question is, what is the difference between:

Car x = new Audi();

and

Car x = new Car();

Answer 1

The difference is

Car = new Car();

gives you a new Car object (it knows only of mCar()), while

Car = new Audi();

gives you a new Audi object, which is also a car object (it knows of mCar() and mAudi()).