How to Choose the Right Azure Service: A Beginner's Map to Compute, Storage, Networking, and Security

Azure gives you more than a dozen ways to run your code, store your data, and connect your services. Picking the wrong one does not break anything immediately. It just costs more, scales worse, and becomes painful to maintain six months later.

This guide maps the most common Azure services to their actual use cases. No marketing language. Just clear guidance on when to use each one and when to pick something else.

Compute: Where Your Code Runs

When You Need Full Control: Virtual Machines

VMs give you a complete operating system. You manage updates, security patches, and configuration. This is the right choice when:

• You're running software that requires a specific OS, like Windows Server with IIS, a custom Linux distro, or GPU workloads
• You're migrating a legacy application that can't be containerized without significant rework
• You need persistent background processes that don't fit the serverless execution model

The trade-off: you manage everything. OS patches, disk management, scaling, and availability are all on you.

When You Want Managed Infrastructure: App Service

App Service handles the infrastructure so you focus on code. Deploy a .NET, Node.js, Python, or Java app and Azure manages the OS, scaling, and SSL.

• Best for web applications and REST APIs that need predictable scaling
• Built-in deployment slots for zero-downtime releases
• Custom domain and SSL included at no extra cost on paid tiers

The free tier is genuinely useful for prototyping. The paid tiers start at ~$13/month for production workloads.

When You Want Pay-Per-Use: Azure Functions

Functions run your code only when triggered, whether by an HTTP request, a queue message, a timer, or a database change. You pay per execution (first 1 million per month free) plus compute duration.

• Ideal for event-driven workloads, such as processing uploaded files, responding to webhooks, or running scheduled jobs
• Maximum execution time: 10 minutes (Consumption plan) or 60 minutes (Premium)
• Cold start latency of 1 to 3 seconds on the Consumption plan, so use Premium if latency matters

For a deeper comparison with AWS Lambda, read our serverless API guide.

When You Want Containers Without Kubernetes: Container Apps

Container Apps sits between App Service and AKS. You deploy containers, Azure handles the orchestration. It scales to zero (no cost when idle) and supports Dapr for microservice communication.

• Best for microservices that need independent scaling
• Scale-to-zero saves money for low-traffic services
• KEDA-based autoscaling responds to queue depth, HTTP traffic, or custom metrics
• No Kubernetes knowledge required, because Azure abstracts the cluster

Storage: Where Your Data Lives

Blob Storage: The Default Choice

If you're not sure which storage service to use, start with Blob Storage. It handles files, images, backups, static website hosting, and data lake storage.

The four access tiers control cost versus retrieval speed:

• Hot (~$0.018/GB): frequently accessed data
• Cool (~$0.01/GB): infrequent access, 30-day minimum
• Cold (~$0.0036/GB): rare access, 90-day minimum
• Archive (~$0.00099/GB): compliance and backup, 180-day minimum, hours to retrieve

Networking: How Services Connect

Security: What Protects Everything

For a full security lab path, read 5 Azure Security Labs Every SC-200 Candidate Should Complete.

How to Pick the Right Service

When you're stuck choosing between two services, ask these three questions:

1. Do I need to manage the OS? No, use App Service or Functions. Yes, use VMs.
2. Is the workload event-driven or always-on? Event-driven, use Functions. Always-on, use App Service or Container Apps.
3. Does my team know Kubernetes? No, use Container Apps. Yes, AKS is an option, but still consider Container Apps first.

The right answer is usually the simplest option that meets your requirements. You can always migrate up the complexity ladder later. Migrating down is harder.

Test Your Knowledge

If you're preparing for AZ-104, service selection questions make up a significant portion of the compute and networking domains. Practice exams with domain-level scoring will show you exactly which service categories need more study:

For a complete study plan, read How to Use Practice Exams to Pass AZ-104 on Your First Try.