You have it right in your title of this post. The black pointer selects an object and the white pointer subselects the "paths and points" of that object.
A funny thing with this is that FreeHand used to have only one pointer that would toggle between the white and black by holding the command key. But to satisfy the Adobe Illustrator users–who were used to multiple arrows–the developers felt the need to split up the pointers on the toolbar. It still works to hold down the command or option keys to toggle.
Also I want to comment on your other post asking if FreeHand is still being sold. Yes it is and you can find some good deals for it online. But I also want to say that there is a class-action lawsuit against Adobe concerning FreeHand. The details are many and you will want to investigate this yourself so go here to learn more.
