Azure Firewall is a managed, cloud-based network security service designed to secure traffic inside and across Azure Virtual Networks. Microsoft describes Azure Firewall as a stateful firewall that “protects Azure Virtual Network resources” by enforcing network and application rules, central logging, and threat intelligence–based filtering. Because it is deployed into a VNet/subnet (often as the hub in a hub-and-spoke), it directly governs East/West and North/South flows to workloads such as Azure virtual machines and platform services reachable through the VNet, using DNAT/SNAT and rule collections. Microsoft guidance highlights capabilities to “centrally create, enforce, and log application and network connectivity policies across subscriptions and virtual networks,” and to filter traffic for peered VNets, branch connections (VPN/ExpressRoute), and internet traffic. These capabilities explicitly map to protecting Azure virtual networks and the VMs and subnets inside them. In contrast, Azure AD users, Exchange Online inboxes, and SharePoint Online sites are SaaS/identity resources protected by Microsoft Entra controls, Exchange/SharePoint security, and Purview/Defender for Office 365—not by a VNet firewall. Therefore, the Azure Firewall–protectable resource types among the options are Azure virtual machines and Azure virtual networks.