While doing some GPO work today and setting up some firewall inbound rules that I want distributed through GP I became confused between these two GPs. They function very similarly, yet I couldn't find any differences.
Computer Configuration > Policies > Windows Settings > Security Settings > Windows Firewall with Advanced Security > Inbound Rules
and
Computer Configuration > Policies > Administrative Templates > Network > Network Connections > Windows Firewall > Domain Profile > Windows Firewall: Define Inbound Port Exception
So, what are their diffrences?
The two different Group Policy locations for Windows Firewall settings are due to feature differences in the Windows Firewall itself between older and newer Windows OS versions.
If you are using Windows Vista/Windows 7/Windows Server 2008 or newer operating systems, use this Group Policy path to configure Firewall policies, as these operating systems have the Windows Firewall "with Advanced Security":
Computer Configuration > Policies > Windows Settings > Security Settings > Windows Firewall with Advanced Security > Inbound Rules
If you are using Windows XP or Windows Server 2003, use only the Group Policy path below to configure Firewall policies. Reason is because these older operating systems have the older Windows Firewall without the "Advanced Security", and only the Group Policy path shown below will work with these older systems.
Computer Configuration > Policies > Administrative Templates >Network> Network Connections > Windows Firewall > Domain Profile > Windows Firewall: Define Inbound Port Exception
I navigated through a ton of research and stumbled across the answer inside this Windows Server 2008 Firewall training video by ITFreeTraining (published on 9/05/2011), where it is explained at the 25:45 mark: Windows Server 2008 Firewall
Unrelated, but since this is a coding Q&A site, you might want to take a look at managing Group Policy through PowerShell.