MS-900 Describe cloud concepts Practice Question
A development team wants to deploy a custom web application to the cloud. They want to upload their code and let the cloud provider handle server infrastructure, operating system updates, and automatic scaling. Which cloud service model best fits this requirement?
⚠ Common exam trap
Candidates often confuse IaaS with PaaS, mistakenly thinking that IaaS also abstracts OS updates and scaling, but IaaS still requires the user to manage the OS and configure scaling manually, unlike PaaS which fully automates these responsibilities.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Platform as a Service (PaaS)
Platform as a Service (PaaS) is the correct choice because it provides a managed hosting environment where the development team can upload their custom web application code without managing the underlying server infrastructure, operating system updates, or scaling. Azure App Service, a PaaS offering, automatically handles OS patching, load balancing, and auto-scaling based on demand, aligning perfectly with the requirement to let the cloud provider handle these tasks.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Infrastructure as a Service (IaaS)
Why it's wrong here
Infrastructure as a Service (IaaS) does provide virtual machines in the cloud, so you could host a custom web app, but the customer still owns the layer above the hypervisor: the operating system, runtime libraries, web server, and the application itself. You must patch the OS, configure virtual networks, and manage capacity and scale, which is exactly the infrastructure operations the team wants to avoid.
- ✓
Platform as a Service (PaaS)
Why this is correct
Platform as a Service (PaaS) is the right fit because it abstracts the underlying compute, storage, and networking into a ready-to-use hosting platform. The developer simply uploads the web app code or a container image, and the provider handles patching the OS, automatic scaling, load balancing, and health monitoring. This lets the team focus on business logic and data rather than on managing servers or runtimes.
- ✗
Software as a Service (SaaS)
Why it's wrong here
Software as a Service (SaaS) delivers fully managed, ready-to-use end-user applications like Microsoft 365 or Dynamics 365, accessed over the internet. These products are consumed as-is; you cannot run or deploy your own custom web application code inside them. At most you can customize behavior through APIs, connectors, or add-ins, but that is not equivalent to hosting a custom app, so it fails the deployment requirement.
- ✗
On-premises deployment
Why it's wrong here
On-premises deployment means running the application on hardware owned and operated by the organization, such as in its own data center. The team would be responsible for the physical servers, network, cooling, power, operating systems, and the full application stack, which is the exact infrastructure burden they need to eliminate. Choosing this option directly contradicts the goal of avoiding infrastructure management.
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This MS-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 MS-900 exam.