Abstract Factory Design Pattern use

I am trying to learn creational design patterns, and i think i understand Factory pattern now. But on moving to Abstract Factory Pattern, I couldn't find its use. I know i miss something with this, but no idea where.

In Abstract Factory Pattern we will have a an Abstract Factory, and Concrete Factories wil return the instance. Suppose we are dealing with creation of Cars. We will have an Abstract Factory like

public interface CarFactory{
    public Car getCar();
}

And our concrete Factories will be something like

public class AudiFactory{
    public Car getCar(){
        return new Audi();
    }
}

public class VolvoFactory{
    public Car getCar(){
        return new Volvo();
    }
}

And in user class we will use it like

CarFactory factory = new AudiFactory();
Car carAudi = factory.getCar();
factory = new VolvoFactory();
Car carVolvo = factory.getCar();

I think we can build the same functionality using Factory Pattern too

public class CarFactory{

    public Car getCar(String make){
    if("Audi".equals(make))
        return new Audi();
    else if("Volvo".equals(make))
        return new Volvo();
    }
}

And in user class we can

CarFactory factory = new CarFactory();
Car carAudi = factory.getCar("Audi");
Car carVolvo = factory.getCar("Volvo");

If my understanding is correct(please correct me if its wrong), Why we need another design pattern for this?