You've been asking a lot of great questions all week
Yes, we go pretty deeply into the details of voters, how they act in authorization decisions, and how and why to customize them or write your own. Basically, voters are responsible for reviewing the authenticated principal's credentials and making a decision (or abstaining) - all votes aggregate from applicable voters and a decision on authorization is reached.
Hope that answers your question!
Author, Spring Security 3 (the Book), Packt Publishing, 2010