bliss works by assessing your music against your rules. Your music is non-compliant if it breaks these rules. If it passes the rules, it's compliant. In many situations bliss knows the steps required to make non-compliant music compliant again, and so it performs the work automatically.
Example: if you enable the album art rule with embedded art you are declaring "I want all of my music to have embedded art". So, if bliss sees an album without art embedded in all of its tracks it will embed it, either from an existing file if you have one or from art found on the Web.
Any other FAQs I forgot or clarifications required? Post your ideas below!