Azure Introduction: Cloud Basics

By the end of this lesson you will be able to explain what cloud computing is, tell IaaS, PaaS and SaaS apart, and describe what Microsoft Azure is and how this course is organised. You do not need an Azure account yet.

What is cloud computing?

Imagine Priya runs a small coaching centre in Jaipur. She wants a website where students can see test results. She has two choices. She can buy a server, keep it in a cupboard, pay for electricity and fix it when the hard disk fails. Or she can rent computing power from a company that already runs huge data centres.

The second choice is cloud computing: renting computers, storage, databases and software over the internet, and paying only for what you use. A data centre is a large building full of servers, with backup power, cooling and security guards.

Think of electricity. You do not build a power plant at home. You plug into the grid and pay the bill each month. The cloud does the same for computers.

Cloud computing gives you five useful things:

• On demand: you create a server in minutes, not weeks.
• Pay as you go: you pay per second, hour or gigabyte, and stop paying when you delete the resource.
• Elastic: you can add more servers during exam-result day and remove them afterwards.
• Global: you can run your app in India, Europe or the US with the same skills.
• Managed: the provider replaces failed disks, patches hardware and guards the building.

IaaS, PaaS and SaaS

Cloud services come in three main service models. The model decides how much work you do and how much the provider does.

A simple way to remember them is food:

IaaS gives you raw building blocks such as virtual machines and networks. You get the most control and the most work. PaaS hides the servers. You upload code, and the platform runs it, patches it and scales it. SaaS is finished software that you just use.

There is also serverless, a style of PaaS where you do not even choose a server size. Azure Functions runs your code only when an event arrives, and you pay per run.

The shared responsibility model

Security in the cloud is shared. The provider protects the physical data centres, the hardware and the network that connects them. You protect what you put on top: your accounts, passwords, data and settings.

The split moves with the service model. With a virtual machine, you must patch the operating system. With App Service, Microsoft patches it for you. In every model, you are responsible for your data, your user accounts and who gets access.

What is Microsoft Azure?

Microsoft Azure is Microsoft's public cloud. It offers hundreds of services: virtual machines, web hosting, databases, storage, AI tools, networking and security services. You manage everything through the Azure portal (a website), the Azure CLI (a command-line tool), PowerShell, SDKs for programming languages, and templates.

Azure is popular with companies that already use Microsoft products, such as Windows Server, SQL Server, Microsoft 365 and Active Directory, because the identity system and licences connect well. It also runs plenty of Linux: you will use Linux examples throughout this course.

If you have studied our AWS tutorial, many ideas will feel familiar. The names change, the concepts stay the same:

A first look at an Azure command

You will learn the Azure CLI properly in a later lesson. Here is a taste. This command asks Azure which account you are signed in to. The output shape was traced from Microsoft's CLI documentation, with made-up IDs.

az account show --query "{name:name, state:state, user:user.name}"

{
  "name": "Azure subscription 1",
  "state": "Enabled",
  "user": "priya@example.com"
}

Azure replies in JSON (JavaScript Object Notation), a text format of keys and values in curly brackets. Almost every Azure tool speaks JSON, so you will see it in every lesson.

Here is the same idea from a PowerShell window, using the separate Az PowerShell module:

Get-AzContext | Select-Object Name, Account

You only need one of these tools. This course uses the Azure CLI with Bash, because it works the same on Windows, macOS, Linux and in the browser.

How this course is organised

You will build skills in the same order a real team does:

1. Understand Azure's structure, regions and the portal.
2. Control who can do what with Microsoft Entra ID and RBAC.
3. Build networks and run compute: VMs, App Service, Functions and containers.
4. Store data in storage accounts and managed databases.
5. Automate with Bicep and GitHub Actions, and watch everything with Azure Monitor.
6. Protect, govern and control costs.
7. Finish with a project: a web app with a database, Key Vault and monitoring, deployed with Bicep.

Common mistakes

• Thinking the cloud is always cheaper. It is cheaper for changing workloads. A server left running all month still costs money, even when nobody uses it.
• Assuming Microsoft secures everything. Microsoft secures the data centre. You secure accounts, data and settings.
• Learning only the portal. Clicking is fine for exploring. Real teams use the CLI and templates so they can repeat the work exactly.

Key points

• Cloud computing means renting computing resources over the internet and paying for what you use.
• IaaS gives you servers to manage, PaaS runs your code for you, and SaaS is finished software.
• Security is shared: Microsoft protects the physical cloud, you protect your data, identities and settings.
• Microsoft Azure is Microsoft's public cloud, managed through the portal, the CLI, PowerShell, SDKs and templates.
• Azure services map closely to AWS services, so cloud skills carry over.

IaaS                   | PaaS                 | SaaS
Linux virtual machine  | Azure App Service    | Outlook email
Virtual network        | Azure SQL Database   | Microsoft Teams