AZ-900 Describe Azure architecture and services Practice Question
A company stores billions of image files that are accessed frequently via HTTP from a web application. They need a highly scalable and durable storage solution with global accessibility. Which Azure storage service should they use?
⚠ Common exam trap
Test-takers frequently confuse Azure Files (which also supports HTTP via REST) with Blob Storage, but Azure Files is primarily a managed file share for SMB/NFS protocols, not optimized for high-scale, HTTP-based object storage of billions of image files.
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
✓
Azure Blob Storage
Azure Blob Storage is designed for storing massive amounts of unstructured data, such as image files, and provides HTTP/HTTPS access via REST APIs. It offers high scalability (up to petabytes), durability (99.9999999999% with LRS/RA-GRS), and global accessibility through a globally unique endpoint and optional CDN integration. This makes it the ideal choice for frequently accessed image files in a web application.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Azure Blob Storage
Why this is correct
Azure Blob Storage is an object storage service designed for massive scale of unstructured data, including billions of image files. It provides native HTTP/HTTPS REST endpoints, allowing any application or client to access individual blobs via a direct URL. Combined with features like geographic redundancy, lifecycle management, and CDN integration, it delivers the high durability, availability, and performance required for internet-scale image serving.
- ✗
Azure Files
Why it's wrong here
Azure Files provides fully managed network file shares based on the SMB and NFS protocols, typically mounted as accessible drives within virtual machines or on-premises environments. While it can store images, it is not optimized for serving millions of discrete files over HTTP to anonymous or external clients, nor does it provide the per-object URL access model of blob storage. Its performance and access methods are designed for shared file systems, not hyper-scale content distribution.
When this WOULD be correct
A company needs to lift-and-shift an on-premises file server to Azure, requiring shared file access for multiple VMs or on-premises clients using standard SMB protocol, without code changes.
- ✗
Azure Queue Storage
Why it's wrong here
Azure Queue Storage is an asynchronous messaging service that holds small messages (up to 64 KB) for reliable communication between application components, not a file repository. It offers no HTTP endpoint for retrieving individual images, and attempting to store billions of image objects would violate its architectural purpose and size limits. It is meant for decoupling workloads, not for durable, globally accessible content storage.
When this WOULD be correct
A company needs to reliably pass messages between application components, such as processing orders from a web frontend to a backend service, with guaranteed delivery and at-least-once processing. Azure Queue Storage would be correct for this asynchronous messaging scenario.
- ✗
Azure Disk Storage
Why it's wrong here
Azure Disk Storage provides block-level storage volumes attached to a single virtual machine, accessible only via the SCSI/IDE protocol from that VM. These managed disks do not expose HTTP endpoints, so they cannot serve images directly to external applications over the internet. To share images from a disk, a VM must run a web server and proxy requests, adding overhead and scalability bottlenecks that Azure Blob Storage eliminates through its native REST API.
When this WOULD be correct
A company needs to attach high-performance, durable storage to an Azure virtual machine for a database or application that requires low-latency, persistent block storage. The question would specify a VM workload, not a web app serving images via HTTP.
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.
✓Azure Blob StorageCorrect answer▾
Why this is correct
Azure Blob Storage is an object storage service designed for massive scale of unstructured data, including billions of image files. It provides native HTTP/HTTPS REST endpoints, allowing any application or client to access individual blobs via a direct URL. Combined with features like geographic redundancy, lifecycle management, and CDN integration, it delivers the high durability, availability, and performance required for internet-scale image serving.
✗Azure FilesWrong answer — click to see why▾
Why this is wrong here
Azure Files provides managed file shares accessible via SMB or NFS, not optimized for serving billions of image files over HTTP with global scalability and durability like Blob Storage.
★ When this WOULD be the correct answer
A company needs to lift-and-shift an on-premises file server to Azure, requiring shared file access for multiple VMs or on-premises clients using standard SMB protocol, without code changes.
Why candidates choose this
Candidates may confuse file storage (Azure Files) with object storage (Blob Storage) for web content, assuming 'files' means image files, but Azure Files is designed for shared file systems, not HTTP-based object serving.
✗Azure Queue StorageWrong answer — click to see why▾
Why this is wrong here
Azure Queue Storage is designed for message queuing and decoupling components in distributed applications, not for storing and serving image files via HTTP. It lacks the blob-level HTTP access and scalability features needed for billions of image files.
★ When this WOULD be the correct answer
A company needs to reliably pass messages between application components, such as processing orders from a web frontend to a backend service, with guaranteed delivery and at-least-once processing. Azure Queue Storage would be correct for this asynchronous messaging scenario.
Why candidates choose this
Candidates may confuse 'storage' in the name with general file storage, or think queue-based access could serve files, overlooking that Queue Storage is for messages, not files.
✗Azure Disk StorageWrong answer — click to see why▾
Why this is wrong here
Azure Disk Storage provides block-level storage for VMs, not HTTP-accessible object storage for billions of image files. It lacks global accessibility and is not designed for web application access via HTTP.
★ When this WOULD be the correct answer
A company needs to attach high-performance, durable storage to an Azure virtual machine for a database or application that requires low-latency, persistent block storage. The question would specify a VM workload, not a web app serving images via HTTP.
Why candidates choose this
Candidates may confuse 'disk' with general storage, thinking it can serve files over HTTP, or they may not understand that Azure Disk Storage is tied to VMs and not globally accessible via HTTP endpoints.
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?”
Quick reference
Azure Blob Storage Tier Comparison
| Tier | Storage Cost | Retrieval Cost | Latency | Use Case |
|---|---|---|---|---|
| Hot | Highest | Lowest | Immediate | Active data, frequent reads |
| Cool | Lower | Higher | Immediate | Data accessed < once / month |
| Cold | Lower still | Higher | Immediate | Data accessed < once / quarter |
| Archive | Lowest | Highest + rehydration delay | Hours | Long-term compliance retention |
Go deeper
Related to this question
Learn chapter
Azure Regions and Geographies
Key term
Blob
A blob is a large piece of unstructured data, like a photo or video, stored in the cloud with a unique identifier.
Key term
Image
An image is a complete snapshot of a system's operating system, applications, and settings, used to deploy or restore computing environments quickly.
About these practice questions
Courseiva writes every AZ-900 question from scratch — 981 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. Learn why practice questions differ from exam dumps →
JA
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.