Cloud Service Models (IaaS, PaaS, and SaaS)
In Part 2, we explored the different types of cloud computing: public, private, and hybrid clouds. Now that we know where cloud services can run, the next step is understanding how cloud services are provided.
These are called cloud service models, and there are three main ones:
•Infrastructure as a Service (IaaS)
•Platform as a Service (PaaS)
•Software as a Service (SaaS)
This post explains each model in simple terms with easy examples.
What Are Cloud Service Models?
Cloud service models describe how much control you have and how much the cloud provider manages for you.
Think of it like renting a home:
•Sometimes you rent an empty house
•Sometimes you rent a furnished house
•Sometimes you stay in a hotel where everything is provided
Cloud service models work in a similar way.
Infrastructure as a Service (IaaS):
Infrastructure as a Service (IaaS) is the most flexible cloud model.
With IaaS:
•The cloud provider supplies the hardware (servers, storage, networking)
•You control the operating system and software
•You manage applications and data
Simple Example:
Using Azure Virtual Machines to create your own server in the cloud.
When IaaS Is Used:
•Running custom applications
•Migrating on-premises servers to the cloud
•Full control over the environment
Key Point: You manage more, the provider manages less.
Platform as a Service (PaaS)
Platform as a Service (PaaS) removes the need to manage infrastructure.
With PaaS:
•The cloud provider manages servers and operating systems
•You focus on building and running applications
•No need to worry about updates or maintenance
Simple Example:
Using Azure App Service to deploy a web application.
When PaaS Is Used:
•Application development
•Faster deployment
•Less system administration
Key Point: You focus on apps, the provider handles the platform.
Software as a Service (SaaS)
Software as a Service (SaaS) is the most common cloud model.
With SaaS:
•Everything is managed by the provider
•You simply use the software
•No installation or maintenance required
Simple Example:
Using Microsoft 365, Outlook, Teams, or OneDrive.
When SaaS Is Used:
•Daily productivity tasks
•Email and collaboration
•Business applications
Key Point: You just sign in and use the software.
Comparing IaaS, PaaS, and SaaS
| Feature | IaaS | PaaS | SaaS |
|---|---|---|---|
| Control | High | Medium | Low |
| Setup effort | High | Medium | Very low |
| Target users | IT admins, engineers | Developers | General users |
| Flexibility | Very high | Moderate | Limited |
| Maintenance | User-managed | Shared | Provider-managed |
As you move from IaaS → PaaS → SaaS, your responsibility decreases and convenience increases.
Why Cloud Service Models Matter
Understanding these models helps you:
•Choose the right cloud service
•Understand real-world cloud environments
•Prepare for cloud certifications
•Build confidence in cloud concepts
IaaS, PaaS, and SaaS are the building blocks of cloud computing. Each model serves a different purpose, and knowing when to use each one is an important cloud skill. Starting with SaaS is common for beginners, while IaaS and PaaS become more important as you grow in cloud knowledge.
What’s Next?
In Part 4, I’ll introduce Microsoft Cloud and explain how Azure, Microsoft 365, and Dynamics 365 fit together.
Thanks for reading, and keep learning step by step