Azure Storage Account Explained: Blob, Files, Queue, and Table Storage

A customer uploads a document to an application. Where does the file go? How is it processed? Where is its status stored?

Azure offers different storage services for each need. This guide explains them through one practical example, so you can understand when to use each service and describe it confidently in an interview.

What is an Azure Storage Account?

A Storage Account is an Azure resource used to create and manage storage services. A standard general-purpose v2 account can contain blob containers, file shares, queues, and tables. The right service depends on the kind of data you have and how your application uses it.

Service	What it stores	Best used for
Blob Storage	Objects such as images, PDFs, videos, and backups	File uploads and archived data
Azure Files	Files in a shared folder	Applications that need a mountable file share
Queue Storage	Messages describing work to be done	Background processing
Table Storage	Structured NoSQL records	Simple, large-scale data lookups

A practical example: Document processing

Imagine a customer uploads a document and requests a report:

1. The application saves the uploaded PDF in Blob Storage.
2. It adds a message to Queue Storage asking a worker to process the document.
3. It records the request status in Table Storage so the customer can see “Pending” or “Completed.”
4. If a legacy reporting system needs the finished report in a shared directory, the worker writes it to Azure Files.

Each service solves a different part of the same application.

1. Azure Blob Storage: Store the document

Blob Storage is Azure’s object storage service. It is designed for data such as documents, images, videos, logs, and backups. Files are stored as blobs inside containers, and applications commonly access them through APIs over HTTPS.

Practical example: A customer uploads identity-document.pdf. The application saves it in a private container named customer-documents. An authorized processing service retrieves it when needed.

DevOps example: An application writes diagnostic files or archived logs to a Blob container. A workload identity is granted the access it needs, so storage credentials do not have to be placed in source code.

Choose Blob Storage when: Your application needs to upload, download, or archive files as objects.

Interview answer: “I use Blob Storage for unstructured data such as uploaded documents, logs, and backups. I organize the objects in containers and grant access according to the application’s requirements.”

2. Azure Files: Share a folder between systems

Azure Files provides managed file shares in the cloud. Compatible systems can mount a share using SMB or NFS, depending on its configuration. This makes it useful for software that expects a file system path or for systems that need to work with shared files. learn.microsoft.com

Practical example: A report-generation server writes completed reports to a shared folder. A separate reporting system reads those files from the same Azure file share.

DevOps example: A legacy application moved to Azure VMs still expects files under a shared directory. Azure Files can provide that directory without managing a separate file server.

Choose Azure Files when: An application needs a mountable shared folder.

Interview answer: “I use Azure Files when multiple systems or a legacy application need access to files through a shared directory.”

Blob Storage versus Azure Files

Question	Blob Storage	Azure Files
How does the application normally access data?	As objects through an API	As files through a mounted share
Common example	Uploading a PDF from a website	Sharing reports between servers

3. Azure Queue Storage: Process work in the background

Queue Storage holds messages until an application worker processes them. It is useful for tasks that do not need to finish before the website responds to the user. A queue message can be up to 64 KB, so the application should send a document ID or reference rather than the document itself.

Practical example: After a customer uploads a PDF, the website adds a message containing documentId: 4821 to a queue. A worker reads the message, gets the PDF from Blob Storage, and processes it. Meanwhile, the website can confirm that the request was received.

DevOps example: An image-processing service receives a sudden increase in requests. The requests wait in a queue while workers process them.

Choose Queue Storage when: You want to pass a task to a background worker and let the user-facing application respond promptly.

Interview answer: “I use Queue Storage to separate the application from background work. The application places a small message in the queue, and a worker processes the task.”

4. Azure Table Storage: Track simple structured data

Table Storage is a structured NoSQL data store. It stores records called entities. A PartitionKey and RowKey together identify an entity, so these keys should be chosen based on how the application will search for records.

Practical example: The application tracks the processing status of a document:

PartitionKey	RowKey	Status	File reference
customer-1042	document-4821	Processing	customer-documents/identity-document.pdf

When processing finishes, the worker changes Status to Completed. The website reads the record to show the customer the latest status.

DevOps example: An operations tool stores job IDs, environments, start times, and results for simple lookups.

Choose Table Storage when: You need to store many simple structured records and know the keys you will use to retrieve them. If you need complex relationships and SQL queries, assess a database service instead.

Interview answer: “I use Table Storage for simple structured data such as job status. I design the partition and row keys around the application’s lookup pattern.”

How the four services work together

Step	Action	Service
1	Customer uploads a PDF	Blob Storage saves it
2	Application requests background processing	Queue Storage holds the task message
3	Website displays the processing status	Table Storage holds the status record
4	Legacy system reads the finished report from a shared path	Azure Files provides the file share

Easy way to remember: Blob = objects · Files = shared folders · Queue = pending work · Table = NoSQL records.

Quick interview questions

What is the difference between a Storage Account and Blob Storage?
A Storage Account is the Azure resource that provides storage services. Blob Storage is one of those services and stores object data.

When would you choose Blob Storage over Azure Files?
Choose Blob Storage when an application handles files as objects through an API. Choose Azure Files when software needs to mount a shared directory.

Would you put a PDF directly into Queue Storage?
No. Put the PDF in Blob Storage and send its ID or reference in the queue message.

Why does Table Storage need a PartitionKey and RowKey?
Together, they identify an entity. Choosing them around your lookup pattern helps the application retrieve records efficiently.