The answer is Infrastructure as a Service (IaaS), as it provides the cloud service model with the most control over the underlying infrastructure. This is because IaaS delivers virtualized computing resources over the internet, granting customers direct administrative access to the operating system, storage, and networking components like virtual networks and firewalls, without requiring physical hardware management. On the Microsoft Azure Fundamentals AZ-900 exam, this concept tests your ability to distinguish service models by responsibility levels—a common trap is confusing PaaS or SaaS for offering similar control, but only IaaS lets you configure the OS and network stack. To remember, think of IaaS as “I am in charge of the infrastructure,” where you handle everything from the OS upward, while the provider manages only the physical hardware. A useful memory tip: “IaaS = I control the stack, PaaS = platform only, SaaS = software ready.”
AZ-900 Describe cloud concepts Practice Question
This AZ-900 practice question tests your understanding of describe cloud concepts. This is a configuration task: choose the command set that satisfies every stated requirement. Small differences — like 'secret' vs 'password' or 'transport input ssh' vs 'all' — change whether the answer is correct. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
Which cloud service model gives customers the most control over the underlying infrastructure, including the operating system and networking?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Infrastructure as a Service (IaaS)
Infrastructure as a Service (IaaS) provides virtualized computing resources over the internet, giving customers direct control over the operating system, storage, and networking components such as virtual networks and firewalls. Unlike higher-level service models, IaaS allows users to manage and configure the underlying infrastructure without physical hardware access, making it the model with the most customer control.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
Software as a Service (SaaS)
Why it's wrong here
SaaS gives the least customer control — the provider manages everything.
✗
Platform as a Service (PaaS)
Why it's wrong here
PaaS abstracts OS and middleware management, giving less control than IaaS.
✓
Infrastructure as a Service (IaaS)
Why this is correct
IaaS gives the most control — customers manage OS, networking, and applications on cloud-provided virtual machines.
Related concept
Read the scenario before looking for a memorised answer.
✗
Function as a Service (FaaS)
Why it's wrong here
FaaS (serverless) gives the least infrastructure control — only the code is managed by the customer.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often confuse PaaS with IaaS because both involve virtual machines, but PaaS hides the OS and networking configuration, whereas IaaS grants full administrative access to those layers.
Detailed technical explanation
How to think about this question
Under the hood, IaaS relies on hypervisors (e.g., Hyper-V, VMware ESXi) to partition physical hardware into virtual machines, each with its own virtualized network interface cards (vNICs) and virtual switches. Customers can configure custom routing tables, network security groups (NSGs), and even bring their own operating system images, which is critical for compliance scenarios like running legacy applications with specific OS patch requirements. In contrast, PaaS and FaaS abstract these layers entirely, enforcing provider-managed updates and network topologies.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
TExam Day Tips
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A media company stores terabytes of video archives that are accessed once a year for audit purposes. Moving these objects to a cold storage tier (Azure Archive, S3 Glacier, or Google Nearline) costs a fraction of hot storage. Questions like this test whether you understand storage tiers, access frequency tradeoffs, and retrieval latency requirements.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this AZ-900 question in full detail.
Describe cloud concepts — This question tests Describe cloud concepts — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Infrastructure as a Service (IaaS) — Infrastructure as a Service (IaaS) provides virtualized computing resources over the internet, giving customers direct control over the operating system, storage, and networking components such as virtual networks and firewalls. Unlike higher-level service models, IaaS allows users to manage and configure the underlying infrastructure without physical hardware access, making it the model with the most customer control.
What should I do if I get this AZ-900 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
This AZ-900 practice question is part of Courseiva's free Microsoft certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the AZ-900 exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.