This image shows a layered overview of the Palo Alto Networks VM-Series firewall architecture.

The first or bottom layer includes the the Palo Alto operating sytem (PAN-OS).

The second layer includes PA-Series hardware, VM-Series software and Prisma Access cloud service.

The third layer features subscription services such as URL filtering, threat prevention, WildFire malware prevention, DNS security, and GlobalProtect.

The fourth or top layer includes Panorama Management.