Practice: AZ-900

Answer: IaaS provides raw compute, storage and networking; the customer manages the OS, middleware and applications. PaaS and SaaS abstract those layers away.

Answer: Microsoft Entra ID is Azure's cloud-based identity and access management service — it authenticates users and controls access to applications and resources.

Answer: Availability Zones are physically separate datacenters within a region with independent power, cooling and networking. Deploying across zones protects against datacenter-level failure.

Answer: The Azure Pricing Calculator models planned services and estimates monthly cost before deployment. Cost Management analyzes spend after deployment.