1. What Are The Rules?
The rules correspond to the scenario and audience by which each retargeting message will be executed.
You can define scenarios for each specific audience. And you can create as many scenarios as you want.
Before creating rules (scenario), you have to create all the channel retargeting messages you want to use in the scenario. See Channels Helpdesk for more details.
There are different type of audiences:
Your audience can only be segmented based on what is referenced in your back office.