Sonar Advanced Mode: Aggressive vs. Automatic

What, if any, is the difference between Sonar Advanced Mode: Aggressive v.  Automatic for Automatic Scanning (which I assume is Real Time Scanning)

Does Automatic switch to Aggressive for suspicious files? Is that what Automatic Means?

Would Aggressive slow-down my browsing or PC.

If I set the response to Ask Me while using Aggressive, I assume that, if I made an intelligent choice, that NS would not delete a necessary or critical file because of a false positive.