OK, so the differences between Xtreme 5 and Xtreme Pro 5, with respect to groups are...what exactly?

"...showing all the objects on the page. The Gallery provides thumbnail views of all objects." Doesn't quite click with me right off.

Are these objects something I would create but not be able to manipulate somehow, or are they predefined objects with layers or effects that can only be edited by the Pro and not the regular version?

Once the light bulb goes on, I'll get it I promise, but it's just not there for me yet.

Is it kind of like the differences between say Photoshop Elements and full on Photoshop, where in Elements you can apply a pre-defined style but not edit the parameters of that style, whereas in full Photoshop you can tweak to your heart's content?