The shared vocabulary behind every AZ-104 topic — service models, regions, and how Azure organizes resources
🟢 Beginner⏱ 10 Minutes📘 AZ-104 · Prerequisites🎧 Audio Available
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Why This Matters
AZ-104 assumes you understand the basic vocabulary of cloud computing — service models, regions, and who is responsible for what. This shows up throughout the exam, especially in questions about availability, disaster recovery, and choosing between services.
Service Models: IaaS, PaaS, SaaS
Model
What the provider manages
What you manage
Azure examples
IaaS (Infrastructure as a Service)
Physical hardware, virtualization, networking
OS, runtime, apps, data
Virtual Machines, Virtual Networks
PaaS (Platform as a Service)
Infrastructure + OS + runtime
Apps and data
App Service, Azure SQL Database
SaaS (Software as a Service)
Everything, including the application
Your data/config only
Microsoft 365, Dynamics 365
Example: Running a web app on a VM you configure yourself (install IIS or nginx, patch the OS) is IaaS. Deploying the same app to App Service — where Azure handles the OS and runtime — is PaaS. AZ-104 covers both (Module 03 – Compute includes VMs and App Service).
The Shared Responsibility Model
As you move from IaaS → PaaS → SaaS, Microsoft takes on more responsibility and you take on less. But security of your data, identities, and access management is always your responsibility, regardless of model. This is why Identity & Governance (Module 01) is weighted so heavily on the exam — it's the part you always own.
Regions, Region Pairs & Availability Zones
A region is a set of Microsoft datacenters in a geographic area (e.g., East US). Most resources are deployed to a specific region.
An availability zone (AZ) is a physically separate datacenter (with independent power, cooling, networking) within a region. Regions that support AZs typically have 3.
A region pair is a pre-defined pairing of two regions in the same geography (e.g., East US ↔ West US) used for disaster recovery — services like geo-redundant storage (GRS) replicate to the paired region.
Example: Deploying VMs across 3 availability zones in East US protects against a datacenter-level failure (power/cooling outage in one building). Enabling GRS on a storage account in East US additionally protects against a regional disaster by replicating data to West US.
You'll see AZs again in Module 03 (VM availability) and region pairs again in Module 02 (storage redundancy) and Module 05 (Azure Site Recovery).
East US (Region)
├── Availability Zone 1 (Datacenter A)
├── Availability Zone 2 (Datacenter B)
└── Availability Zone 3 (Datacenter C)
Protects against datacenter failure
Region Pair
East US ⇄ West US
GRS replication target
Protects against regional disaster
Resource Hierarchy (Preview)
Azure organizes everything under a hierarchy:
Management Group
└── Subscription
└── Resource Group
└── Resource (VM, storage account, VNet, ...)
Module 01 covers this hierarchy in depth (management groups, subscriptions, resource groups, and how policies/RBAC apply at each level). For now, just know that every resource you create in these labs lives inside a resource group — which is why every lab's cleanup step is "delete the resource group."
How This Connects to Other Topics
Glossary
Unfamiliar term? Check the AZ-104 Glossary for quick definitions of every concept used across these docs.
Module 01 — Identity & Governance
The resource hierarchy above (management groups → subscriptions → resource groups) is covered in depth in Management Groups & Azure Policy.
Key Takeaways
💡 Summary
IaaS / PaaS / SaaS = how much Microsoft manages vs. you
Shared responsibility = security of data & identity is always yours
Region = a geographic area of datacenters
Availability Zone = a physically separate datacenter within a region
Region pair = two regions used together for disaster recovery (e.g., GRS)
Resource hierarchy = Management Group → Subscription → Resource Group → Resource
Next Steps
Learn: Read this doc (you're here)
Continue: Read Networking Basics (IP addressing, subnets, DNS — needed for Module 04)