Cloud Concepts and the Azure Architecture Landscape
Core cloud model
Azure is a consumption-based cloud platform. Candidates must distinguish IaaS, PaaS, and SaaS, and understand the shared responsibility model: the provider secures the physical layer while the customer owns identity, data, and configuration. Key characteristics include elasticity, scalability, pay-as-you-go billing, and global reach.
Azure hierarchy and geography
Know the resource hierarchy: tenant → management groups → subscriptions → resource groups → resources. Azure Resource Manager (ARM) is the control plane; Bicep and ARM templates are declarative deployment tools. Geographically, Azure is organized into geographies, regions, availability zones, and edge locations. Region pairs provide disaster-recovery guidance, but not every service is available in every region or zone.
Traps
Questions often confuse availability zones with region pairs, treat all services as globally available, or imply that PaaS removes all customer responsibility. Another common trap is assuming a resource group is a security boundary; RBAC and policy are. Also separate the control plane (ARM) from the data plane (service operations).
Worked example
A team needs a workload with 99.99% availability and disaster recovery across geographies. Putting all resources in one region with three availability zones improves in-region resilience but not regional disaster recovery. A better answer combines zone-redundant services with a paired region for backup and failover, provided the chosen services support both.
Rule of thumb
If you patch the OS, it is IaaS; if the platform patches and scales it, it is PaaS; if you only configure and use the application, it is SaaS. Match the service to the responsibility you are willing to own.