AZ-900: Azure Fundamentals — Study Guide

Exam Overview#

Domain Weightings#

---

Domain 1: Cloud Concepts (25–30%)#

Cloud service models#

Cloud deployment models#

• Public cloud — shared infrastructure (Azure, AWS, GCP). Pay as you go, elastic.
• Private cloud — dedicated infrastructure (on-premises data centre). Full control, high cost.
• Hybrid cloud — mix of public and private. Use Azure Arc or VPN/ExpressRoute to connect.

Benefits of cloud#

• High availability — SLAs guarantee uptime; deploy across availability zones.
• Scalability — vertical (bigger VM) + horizontal (more VMs).
• Elasticity — automatically scale in/out based on demand.
• Reliability — geo-redundant services.
• Predictability — consistent performance and pricing.
• Security — shared responsibility model; cloud providers handle physical security.
• Governance — Azure Policy, RBAC, Management Groups for compliance.
• Manageability — portal, CLI, APIs, ARM templates.

Consumption-based model#

• Capital Expenditure (CapEx) — upfront investment in physical hardware.
• Operational Expenditure (OpEx) — pay for what you use. Cloud is OpEx.

---

Domain 2: Azure Architecture and Services (35–40%)#

Global infrastructure#

• Region — geographical area with one or more datacentres (e.g., East US, UK South). Over 60 regions globally.
• Region pair — each region is paired with another in the same geography for disaster recovery (East US ↔ West US).
• Availability Zone — physically separate datacentres within a region (power, cooling, network). Protect against single datacentre failure.
• Azure Geography — a market (e.g., United States, Europe) preserving data residency.

Resource organisation#

Azure Account
└── Management Groups (optional — org-wide governance)
    └── Subscriptions (billing + access boundary)
        └── Resource Groups (logical container)
            └── Resources (VMs, storage, etc.)

Core compute services#

Core storage services#

Storage account redundancy#

Core networking services#

Core database services#

AI and ML#

• Azure Machine Learning — build, train, deploy ML models.
• Azure Cognitive Services — pre-built AI APIs (vision, speech, language, decision).
• Azure Bot Service — build conversational AI bots.

DevOps and monitoring#

• Azure DevOps — Boards, Repos, Pipelines, Test Plans, Artifacts.
• GitHub Actions — CI/CD integrated with GitHub.
• Azure Monitor — metrics, logs, alerts for all Azure resources.
• Azure Advisor — personalised best practice recommendations (cost, security, reliability).

---

Domain 3: Azure Management and Governance (30–35%)#

Cost management#

• TCO Calculator — estimate cost savings of moving from on-premises to Azure.
• Azure Pricing Calculator — estimate cost of specific Azure services.
• Azure Cost Management — analyse and optimise actual Azure spend.
• Azure Advisor — identifies idle resources and savings opportunities.

Factors affecting cost: resource type, region, tier/SKU, bandwidth (egress charged), support plans.

Azure governance tools#

Azure Security tools#

Shared responsibility model#

SLAs and the Composite SLA#

An SLA (Service Level Agreement) defines the uptime guarantee for each Azure service.

Composite SLA — when your app depends on multiple services, multiply their SLAs:

• App Service (99.95%) × SQL Database (99.99%) = 99.94% composite SLA

To increase availability: deploy across Availability Zones or use redundant components.

---

Study Plan (2–3 Weeks)#

Week 1: Cloud Concepts + Architecture#

• Microsoft Learn: AZ-900 learning path (free, official)
• Focus: IaaS/PaaS/SaaS, cloud benefits, global infrastructure
• Practice: identify which service model a given scenario uses

Week 2: Azure Services#

• Work through each service category (Compute, Storage, Networking, Database)
• Use the Azure Free Account to explore services hands-on
• Flash cards for service names → use cases

Week 3: Governance + Practice Tests#

• Azure Policy, RBAC, Cost Management, SLAs
• Take 3+ full practice exams (MeasureUp, Whizlabs, Microsoft practice assessment)
• Review every wrong answer — understand why

---

Key Resources#

---

Common Exam Traps#

• IaaS vs PaaS — Azure VMs = IaaS; App Service = PaaS. Know this cold.
• Availability Zones vs Region Pairs — AZs protect against datacentre failure; region pairs protect against regional disaster.
• CapEx vs OpEx — cloud = OpEx (operational); on-premises hardware = CapEx (capital).
• "Which supports hybrid cloud?" — Azure Arc (manage on-prem resources in Azure), VPN Gateway, ExpressRoute.
• NSG vs Azure Firewall — NSG is a basic IP/port filter; Azure Firewall is a full stateful Layer 7 firewall.
• SLA for Free tier services — Microsoft does not provide SLAs for free tier/Dev tier services.