As as newbie I have a question about the left & right inner sidebar versus the left & right sidebar. Can someone explain how they function and what will happen if I make changes to one and not the other?

I am questioning this because when I downloaded the theme I only see two-sidebars one on the left of the content and one on the right. Thank you

Prior to release 3.4, Atahualpa had only two sidebars,right and left. Several people wanted to be able to hav two sidebars on one side, so the theme now offers 4 sidebars that you can use. WordPress defaults to displaying several widgets in the left and right sidebars until you add widgets of your choice. You can use what ever combination of sidebars you choose.