What is Site Authorization??

What is Site Authorization??
i read my september optimization report it has written that use site authorization i read that but i didn't understand what is that.
is it for blocking ads from any site or including ads from any site please answer this question i also searched it at dp but i cant find the answer so please help me.

 

its allowing google adsense bot to access protected pages like a registered user

 

for example if you have a forum you can create a dummy account and give it to google in order to index it

 

so what is the benefit of it??

 

more pages in the index which eventualy leads to more visitors

 

is there any relation with ads keywords?

 

I have a problem with this I'm using my adsense account with another Email id and webmaster's account which is for sitemap's is a different one. Hence effectively I cannot use this feature.