Simple definition
Intune firewall policies configure Microsoft Defender Firewall behavior and rules on managed endpoints.
Purpose and use
An Intune firewall policy manages native filtering features supported on the managed platform.
How does it work?
Profiles and rules specify relevant traffic, programs, ports and network contexts according to available settings.
Example and verification
After deployment, test allowed and blocked flows on the endpoint, including tools required for remote administration.
Points to watch
A rule may not apply to the active network profile or can interact with other local and centralized rules.
In short
The useful outcome is actual filtering behavior across the endpoint's network contexts.