In NIS 2009, Clarify Norton Insight Scan and Insight Submission

In NIS 2009, can someone please clarify for me what an "Insight Scan" is?   Exactly, WHAT is it scanning (ALL FILES ON DISK, running processes, non-running executables and related .DLL fiLES, etc.), and for what purpose?  

 

Also what is an "Insight Submission" and how does it relate to the "Insight Scan", if at all?

 

Lastly, is it NECESSARY for the user to periodically open the "Norton Insight" window AND/OR press the "Refresh" button for the "Norton Insight" to function efficiently using any updated information?  Or is this all done in the background automatically?