Firewall "Program Rules" - Difference between Allow, Block, etc

I know this must sound like a typical newbie question... but I have put in these words both in the internal Help search inside Norton 360 as well as their website... and I can find no concise comparison of what actually is blocked, vs. allowed, etc. with these settings. Can some kind sould please tell me where to look. I couldn't find it inside 360 (sorry to repeat this, but I found it astounding how unhelpful Norton's 360 internal help was...).  Actually, as I reflect on it, it's even worse. Apparently there's no "internal" help system... it just ports you over to the internet.  Suppose someone was "out in the wild" or anywhere else that had no wi-fi, or, egads they didn't have wi-fi capabilities, then how would they get help if they pressed F1 on their computer, inside 360?  Just wondering.

 

Anyone who can point me towards where Norton seems to have this information inside their convoluted help system would be greatly appreciated.

 

Nathaniel