AZ-900 Course Notes

AZ-900 cloud concept questions usually test comparisons. If the question says resources can grow or shrink as demand changes, think elasticity. If it says adding more instances or capacity to handle more users, think scalability. If it says an app stays available during a datacenter problem, think high availability or fault tolerance instead of cost savings.

AZ-900 management questions often ask which tool matches the job. Use the Azure portal when the clue says web-based graphical interface. Use Azure CLI or Cloud Shell when the clue says command line or scripting. Use Bicep or infrastructure as code when the clue says repeatable deployments, templates, or describing resources in files.

Azure architecture questions often ask which container or boundary is being described. A resource group holds related resources for one app or workload. A subscription is the billing and access boundary. A management group sits above subscriptions so governance can be applied to many subscriptions. If the question says organize multiple subscriptions, do not pick resource group.

Azure service questions are usually about recognizing what problem the service solves. Virtual Machines are the answer when the workload needs operating system control. App Service is the answer for managed web apps and APIs. Functions is the answer for short event-driven code. If the question says container orchestration or managing many containers, AKS is the likely service, but AZ-900 does not expect deep Kubernetes administration.

Governance questions ask how Azure is organized and controlled. Subscriptions separate billing, access, and resource limits. Management groups organize multiple subscriptions. Resource groups organize related resources. Azure Policy enforces rules such as allowed regions or required tags. If the clue says organize many subscriptions, choose management groups; if it says enforce a rule, choose Policy.

Cloud model questions on AZ-900 reward simple keyword matching. Virtual Machines mean IaaS because the customer manages the OS. App Service, Azure SQL Database, and managed database platforms feel like PaaS because Microsoft manages more of the platform. Microsoft 365-style complete apps are SaaS. If the question asks who manages the application itself, SaaS is usually the answer.