Auto-Solve Mode - need better explanation

Hey folks,

     This relates to all versions, so I won't bore you with all details.

     Just wondering if someone can better explain when and when not to use Auto-Solve Mode, for example, why do I need this on just to move a block in a sketch that is not defined in any way, just a totally undimentioned, unconstrained sketch with no relations.

Thoughts?

Thanks,

Brian

SolidworksSketching