AZ-900 Describe cloud concepts Practice Question
A company wants to use a cloud service that provides a fully managed database, including automated backups, patching, and high availability, without managing any underlying servers. Which cloud service model is this?
⚠ Common exam trap
Candidates often confuse PaaS with IaaS because both can host databases, but IaaS requires the customer to manage the OS, database software, and patching, whereas PaaS abstracts all server management away.
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)
This scenario describes a fully managed database service where the provider handles backups, patching, and high availability, and the customer does not manage any underlying servers. This is the definition of Platform as a Service (PaaS), which provides a managed platform (including database engines like Azure SQL Database) where the customer only manages data and schema, while the provider handles the OS, runtime, and infrastructure.
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
IaaS offers virtual machines, storage, and networking, but you are responsible for installing and administering the database software yourself. For example, setting up SQL Server on an Azure VM means you must manage the OS, apply database patches, configure backups, and handle failover. Consequently, IaaS gives you control but falls short of the 'fully managed database' requirement in the question.
When this WOULD be correct
A company needs to migrate an on-premises application to the cloud and requires full control over the operating system, middleware, and database configuration, while still benefiting from scalable virtual machines and storage. The question would specify that the customer manages the database software and OS.
- ✓
Platform as a Service (PaaS)
Why this is correct
PaaS provides a managed platform that includes fully managed database services such as Azure SQL Database. The cloud provider handles the underlying infrastructure, including OS patches, backups, replication, and high availability, while you simply configure the database and connect your applications. This lets you focus on data models and queries instead of database administration tasks.
- ✗
Software as a Service (SaaS)
Why it's wrong here
SaaS delivers complete, ready-to-use applications such as Microsoft 365 or Salesforce over the internet. Although the software stores data in a database, you have no direct access to manage that database—it is an internal component of the service. Thus, SaaS is not a managed database offering; it is an application delivery model that happens to include a database behind the scenes.
When this WOULD be correct
A company wants to use a cloud-based email service, customer relationship management (CRM) tool, or office productivity suite without managing any software or infrastructure. The question would specify that the service is a complete application for end users, not a development or database platform.
- ✗
Container as a Service (CaaS)
Why it's wrong here
CaaS platforms like Azure Container Instances or Azure Kubernetes Service let you deploy and orchestrate containers, but the database remains your responsibility inside those containers. You must manage container images, persistent storage, database backups, and scaling even though the container runtime is managed. Therefore, CaaS provides container orchestration, not a fully managed database service.
When this WOULD be correct
A company wants to deploy containerized applications using Docker and Kubernetes, and they need a service that manages the container orchestration platform, scaling, and networking, but they are responsible for the application code and container images. In this scenario, CaaS (e.g., Azure Container Instances, Amazon ECS) would be the correct answer.
Option-by-option analysis
Why each answer is right or wrong
Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The AZ-900 exam frequently reuses these exact scenarios with slightly different constraints.
✓Platform as a Service (PaaS)Correct answer▾
Why this is correct
PaaS provides a managed platform that includes fully managed database services such as Azure SQL Database. The cloud provider handles the underlying infrastructure, including OS patches, backups, replication, and high availability, while you simply configure the database and connect your applications. This lets you focus on data models and queries instead of database administration tasks.
✗Infrastructure as a Service (IaaS)Wrong answer — click to see why▾
Why this is wrong here
IaaS provides virtualized servers, storage, and networking, but the customer is responsible for managing the operating system, database software, backups, and patching. The question specifies a fully managed database without managing any underlying servers, which is not IaaS.
★ When this WOULD be the correct answer
A company needs to migrate an on-premises application to the cloud and requires full control over the operating system, middleware, and database configuration, while still benefiting from scalable virtual machines and storage. The question would specify that the customer manages the database software and OS.
Why candidates choose this
Candidates may confuse IaaS with PaaS because both involve cloud infrastructure, but IaaS requires more management. The phrase 'fully managed database' might be overlooked, leading to the assumption that any cloud service is IaaS.
✗Software as a Service (SaaS)Wrong answer — click to see why▾
Why this is wrong here
SaaS provides ready-to-use software applications, not a managed database platform. The question specifies a fully managed database service, which is a platform capability (PaaS), not an application delivered to end users.
★ When this WOULD be the correct answer
A company wants to use a cloud-based email service, customer relationship management (CRM) tool, or office productivity suite without managing any software or infrastructure. The question would specify that the service is a complete application for end users, not a development or database platform.
Why candidates choose this
Candidates may confuse 'fully managed' with 'software as a service,' thinking that any managed service is SaaS, without distinguishing between managing a platform (PaaS) versus providing an application (SaaS).
✗Container as a Service (CaaS)Wrong answer — click to see why▾
Why this is wrong here
Container as a Service (CaaS) provides container orchestration and management, but the question specifies a fully managed database with automated backups, patching, and high availability without managing servers. CaaS still requires you to manage the database software and configuration, whereas PaaS offers a fully managed database service.
★ When this WOULD be the correct answer
A company wants to deploy containerized applications using Docker and Kubernetes, and they need a service that manages the container orchestration platform, scaling, and networking, but they are responsible for the application code and container images. In this scenario, CaaS (e.g., Azure Container Instances, Amazon ECS) would be the correct answer.
Why candidates choose this
Candidates may confuse CaaS with PaaS because both abstract infrastructure, but CaaS focuses on containers rather than fully managed services like databases. The term 'managed' in the question might lead them to think of container management services.
Analysis generated from the official AZ-900blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
Go deeper
Related to this question
Learn chapter
What is Cloud Computing?
Key term
PaaS
Platform as a Service (PaaS) is a cloud computing model that provides a managed platform for developers to build, run, and manage applications without dealing with the underlying infrastructure.
Key term
Availability
Availability is the measure of how often a system or service is operational and accessible when needed, typically expressed as a percentage of uptime.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
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.