[ Thanks to Falko
Timme for this link. ]
“A firewall object is designed to represent a real
firewall device in your network. This firewall object will have
interface and IP address objects that mirror the real interfaces
and IP addresses of the actual device. In addition, the firewall
object is where you create the access policy rule sets, NAT rule
sets, and routing rule sets that you assign to your firewall
device.“By default, a firewall has one Policy rule set, one NAT rule
set, and one routing rule set. However, you can create more than
one rule set using branching rules (for firewalls that support
them). On the other hand, you don’t have to populate all the rule
sets. You can, for example, create a Policy ruleset and leave the
NAT and Routing rule sets empty. We explains more about policies
and rule sets below.”