Azure AZ-900 glossary of cloud concepts, services, governance, pricing, and support terms.
Use this glossary when Azure terms start to blur together. Keep it beside the cheat sheet and resources instead of turning it into a substitute for study.
| Term | Short meaning | Why it matters on AZ-900 |
|---|---|---|
| Availability Zone | Isolated location inside an Azure region used for resilience | Core Azure resiliency concept |
| CapEx | Up-front capital spending model common in on-premises environments | Cloud-economics contrast term |
| OpEx | Ongoing operational spending model common in cloud consumption | Cloud consumption model term |
| Management group | Governance layer above subscriptions | Tested in hierarchy and governance questions |
| Region pair | Microsoft-defined regional pairing for some resilience patterns | Commonly confused with Availability Zones |
| Resource group | Logical container for related Azure resources | Core Azure management boundary |
| SaaS | Software as a Service; provider manages the finished application | Cloud-service model classification |
| PaaS | Platform as a Service; provider manages more of the runtime platform | Helps separate managed platform fit |
| IaaS | Infrastructure as a Service; customer manages more of the stack | Foundational cloud model |
| SLA | Service Level Agreement, the promised service-availability target | Used in basic availability math and service comparison |
| TCO | Total cost of ownership comparison tool or cost concept | Common cost-management concept |
| Microsoft Entra ID | Azure identity platform formerly known as Azure AD | Core identity term |
| RBAC | Role-based access control for assigning permissions at scope | Core authorization concept |
| Azure Policy | Governance tool that evaluates or enforces allowed configurations | Core governance concept |
| Resource lock | Azure control that helps prevent accidental deletion or modification | Commonly confused with RBAC and Policy |
| Subscription | Billing and management boundary for Azure resources | Core scope term |
| Azure Advisor | Azure recommendation service for reliability, security, performance, cost, and ops | Common management-tool answer |
| Azure Monitor | Monitoring platform for metrics, logs, and alerts | Core observability term |
| Azure Service Health | Service that shows health issues and planned maintenance affecting Azure services | Commonly confused with Azure Monitor |
| Zero Trust | Security model based on verifying explicitly and limiting access | Modern identity and security framing term |
| Pair | Keep this distinction clear |
|---|---|
| subscription vs resource group | billing and management boundary versus logical resource container |
| management group vs subscription | higher governance layer versus workload and billing boundary |
| RBAC vs Azure Policy | who can do something versus what is allowed |
| region vs availability zone | geography boundary versus isolated location inside it |
| TCO vs pricing calculator | migration or comparison model versus service-price estimation |
| Azure Policy vs resource lock | compliance/configuration guardrail versus hard protection against change |
| Azure Monitor vs Azure Service Health | monitor metrics/logs/alerts versus Azure platform incident visibility |
| Entra ID vs RBAC | identity directory/authentication platform versus Azure resource authorization |
| Cluster | Fast separation |
|---|---|
| management group / subscription / resource group | higher governance scope, billing scope, or logical resource container |
| RBAC / Policy / lock | who can act, what is allowed, or what cannot be changed easily |
| region / availability zone / region pair | geography boundary, isolated intra-region location, or paired-region continuity concept |
| pricing calculator / TCO / Cost Management | estimate price, compare broader economics, or track and control spend |
| Entra ID / Conditional Access / MFA | identity directory, access condition control, or stronger sign-in verification |
| Cluster | What it usually signals on the exam |
|---|---|
| IaaS / PaaS / SaaS | service-model classification |
| region / zone / region pair | resiliency and architecture questions |
| management group / subscription / resource group | governance and scope questions |
| RBAC / Policy / lock | access, guardrails, and protection questions |
| pricing / TCO / cost tools | cost and management questions |
| Topic family | Best page to revisit |
|---|---|
| service-family recognition | Cheat Sheet |
| current Microsoft facts and official learning links | Resources |
| exam pacing and review order | Study Plan |
| overall exam framing | Guide root |