IaaS, PaaS, and SaaS Explained
Break down the three cloud service models with real-world examples, and understand which layer of the stack each model abstracts away from you.
IaaS, PaaS, and SaaS Explained is a free Cloud & IT Cert Prep lesson on CoddyKit — lesson 2 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Cloud & IT Cert Prep learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.
The Cloud Service Model Stack
Cloud services come in three flavours — IaaS, PaaS, and SaaS. They differ in how much of the stack the provider runs for you, from raw hardware up to a finished app.
IaaS: Infrastructure as a Service
IaaS rents you virtual machines, storage, and networking. You manage the OS and everything above; Azure handles the physical hardware. The VM is yours to control.
# IaaS example: create a VM (you manage OS and above)
az vm create \
--resource-group myRG \
--name myIaaSVM \
--image Win2022Datacenter \
--size Standard_B2sWho Manages What in IaaS?
With IaaS, Azure runs the hardware and virtualisation, while you handle the OS, apps, and data. That makes it perfect for lifting an existing app into the cloud.
PaaS: Platform as a Service
PaaS goes a step higher — Azure runs the OS and runtime, so you just push your code and data. The command below deploys a web app with the platform fully managed.
# PaaS example: deploy a web app (OS and runtime managed by Azure)
az webapp up \
--name myWebApp \
--resource-group myRG \
--runtime 'NODE:20-lts'PaaS Use Cases and Benefits
PaaS is great when you want to ship fast without minding servers — think App Service or Azure SQL. The trade-off: less control over the underlying OS.
SaaS: Software as a Service
SaaS is a ready-to-use app you just sign in and use — Microsoft 365 or Salesforce. The provider runs absolutely everything for you.
Comparing the Three Models
Think of it as pizza: IaaS is raw ingredients you cook, PaaS is half-baked so you add toppings, and SaaS arrives ready to eat. More managed means less control. 🍕
Azure Services Mapped to Each Model
Most services slot into one model: VMs and disks are IaaS, App Service and Functions are PaaS, and Microsoft 365 is SaaS. Some, like AKS, blend them.
Choosing the Right Service Model
Pick your model by control and speed: IaaS for full OS access, PaaS to move fast, SaaS for standard software. Many teams happily use all three.
Serverless as an Extension of PaaS
Serverless takes PaaS further — with Azure Functions you forget about servers entirely. Code runs on demand, scales to zero, and you pay only per execution.
# Azure Functions: HTTP-triggered function snippet
module.exports = async function (context, req) {
context.res = {
body: 'Hello from Azure Functions!'
};
};Responsibility Matrix Summary
Quick map of who manages what: IaaS = you own OS and up, PaaS = you own apps and data, SaaS = you own only your data and access.
Quick Check
Quick check time! Let us see if IaaS, PaaS, and SaaS feel clear now.
Lesson Recap
Quick recap: IaaS gives raw infra you manage, PaaS lets you focus on code, and SaaS hands you a finished product with the provider running everything.
Frequently asked questions
Is the “IaaS, PaaS, and SaaS Explained” lesson free?
Yes — the full text of “IaaS, PaaS, and SaaS Explained” is free to read here on the web, and the Cloud & IT Cert Prep course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Cloud & IT Cert Prep course, upgrade to CoddyKit PRO.
What will I learn in “IaaS, PaaS, and SaaS Explained”?
Break down the three cloud service models with real-world examples, and understand which layer of the stack each model abstracts away from you. You practise Cloud & IT Cert Prep with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start Cloud & IT Cert Prep?
No prior experience is required. Cloud & IT Cert Prep on CoddyKit is structured for beginners through advanced learners; this is — lesson 2 of 4, so you can start here or from the beginning and move at your own pace.
How long does the “IaaS, PaaS, and SaaS Explained” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this Cloud & IT Cert Prep lesson?
Yes. Every Cloud & IT Cert Prep lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- Cloud vs. Traditional On-Premises
- IaaS, PaaS, and SaaS Explained
- Public, Private, and Hybrid Cloud
- Key Cloud Benefits and Economies of Scale