Domain 1 of the AZ-900 Microsoft Azure Fundamentals exam covers Cloud Concepts, accounting for 25-30% of all exam questions. This study guide covers every testable sub-topic: cloud computing definitions, the shared responsibility model, IaaS/PaaS/SaaS service types, public/private/hybrid deployment models, and the seven cloud benefits Microsoft tests most often.
Cloud Concepts is the first and largest domain on the AZ-900 Microsoft Azure Fundamentals exam, accounting for 25-30% of all exam questions. If you skip this domain, you are leaving roughly one-third of the exam to chance. Practice with the free AZ-900 practice test on PracticeTestGeeks (300+ questions with answer explanations).
Domain 1 tests your ability to define what cloud computing is, articulate its core benefits, and distinguish between the major service and deployment models. These are conceptual questions — no hands-on Azure portal work required — which makes them approachable but also surprisingly tricky. Microsoft tests precise vocabulary.
The official Microsoft definition: Cloud computing is the delivery of computing services — including servers, storage, databases, networking, software, analytics, and intelligence — over the internet to offer faster innovation, flexible resources, and economies of scale.
The key phrase is over the internet. Cloud computing replaces on-premises hardware ownership with on-demand access to a shared pool of configurable resources. You pay for what you use (the consumption-based model) rather than purchasing and maintaining physical infrastructure.
For a broader foundation, see the AZ-900 Complete Exam Guide, which covers all five domains in one place.
Facts verified Oct 25, 2026 against Microsoft. Dates that have passed are removed automatically.
| Item | Detail | Official source |
|---|---|---|
| Time limit | 45 minutes (65-minute seat time) | Microsoft |
| Time limit (seat time) | 65 minutes seat time | Microsoft |
| Passing score | 700 on a 1–1,000 scale | Microsoft |
| Retake fee | Payment required for each retake (if applicable) | Microsoft |
| Validity | Does not expire | Microsoft |
| Renewal | No renewal required | Microsoft |
| Delivery | Pearson VUE (all candidates) or Certiport (students and educators) | Microsoft |
| Eligibility | No formal prerequisite; IT experience recommended | Microsoft |
| Registration opens | Schedule up to 90 days in advance | Microsoft |
Facts verified Oct 25, 2026 against Microsoft. Dates that have passed are removed automatically.
Interactive AZ-900 resources on PracticeTestGeeks, free to start:
The shared responsibility model defines who is accountable for what in a cloud environment. Microsoft divides responsibilities between the cloud provider (Microsoft Azure) and the customer. The split depends on the service model.
| Responsibility | IaaS | PaaS | SaaS |
|---|---|---|---|
| Physical datacenter, network, hosts | Azure | Azure | Azure |
| Operating System | Customer | Azure | Azure |
| Network Controls | Customer | Shared | Azure |
| Applications | Customer | Customer | Azure |
| Data & Identities | Customer | Customer | Customer |
One rule that never changes: The customer is always responsible for their own data and user identities, regardless of whether they use IaaS, PaaS, or SaaS. Azure is always responsible for the physical hardware and datacenters.
The AZ-900 exam tests three deployment models. Know the definitions and the trade-offs:
Resources are owned and operated by a third-party cloud provider (like Microsoft Azure) and delivered over the internet. Multiple organizations share the same physical infrastructure, though data and workloads remain logically isolated. No CapEx required — you pay only for what you use.
Cloud infrastructure is provisioned exclusively for one organization. It can be hosted on-premises in the organization own datacenter or by a third-party provider, but dedicated hardware is not shared with anyone else.
Combines public and private cloud environments with orchestration between them. Organizations keep sensitive workloads on-premises (private) while bursting to the public cloud for additional capacity or hosting less-sensitive applications publicly.
For a full domain-by-domain breakdown, the AZ-900 Study Guide 2026 organizes prep by exam weight and covers all domains systematically.
For a fuller set of questions on this topic, see our microsoft az 900 practice test resource.
For a fuller set of questions on this topic, see our az 900 pdf resource.
For a fuller set of questions on this topic, see our azure fundamentals (az-900) resource.
One of the most-tested concepts in Domain 1 is the shift from Capital Expenditure (CapEx) to Operational Expenditure (OpEx).
CapEx (Capital Expenditure) is upfront spending on physical infrastructure: servers, racks, cabling, cooling. You pay once, own the asset, and depreciate it over time. You also guess future capacity needs — often over-provisioning (waste) or under-provisioning (bottleneck).
OpEx (Operational Expenditure) is ongoing spending for services consumed — pay-as-you-go. Cloud computing converts most IT spending from CapEx to OpEx. No upfront hardware purchase, no depreciation schedule, and you scale costs directly with usage.
The consumption-based model means you only pay for what you use. Azure meters CPU hours, GB of storage, data egress, API calls — all billed by consumption. This directly enables cost predictability: if usage drops, costs drop automatically.
For a complete walkthrough of exam preparation strategy, read How to Pass the AZ-900 Exam in 2026 — it includes a realistic study timeline and resource list.
You can also supplement your Domain 1 prep with a full AZ-900 Practice Test to identify which cloud concepts need more review before exam day.
Try these questions from our free AZ-900 practice tests. The correct answer and an explanation follow each question.
Which cloud deployment model combines on-premises infrastructure with public cloud resources?
Answer: A. Hybrid cloud
A hybrid cloud connects on-premises (private) infrastructure with public cloud services.
A company wants to migrate its existing on-premises servers to the cloud to gain more flexibility and scalability. They want to maintain full control over the operating systems and installed software. Which cloud service model is the most appropriate choice for this scenario?
Answer: B. Infrastructure as a Service (IaaS)
Infrastructure as a Service (IaaS) is the ideal model for migrating existing on-premises workloads, often referred to as 'lift and shift'. [11] It allows the company to rent IT infrastructure—servers and virtual machines (VMs), storage, networks, and operating systems—from a cloud provider on a pay-as-you-go basis, while still managing the OS and applications. [27]
A large financial institution needs to keep its sensitive customer data in a private, on-premises datacenter to meet strict regulatory requirements. However, they also want to leverage the scalability and services of the public cloud for their new, less sensitive marketing applications. Which cloud deployment model would best suit their needs?
Answer: D. Hybrid Cloud
A hybrid cloud combines a private cloud (or on-premises infrastructure) with a public cloud, allowing data and applications to be shared between them. [9] This model offers organizations greater flexibility and more deployment options, enabling them to keep sensitive data on a private network while using the public cloud for other workloads. [26, 31]