This lesson breaks down the three major cloud service models—IaaS, PaaS, and SaaS—so you can quickly understand who manages what, how much control you get, and which option best fits a workload.
The control, speed, and trade-offs behind the most common cloud delivery models.
Most cloud architecture, budgeting, and security decisions start with choosing the right service layer.
This is a core concept in AZ-900, AWS Cloud Practitioner, and real cloud support or admin work.
Cloud computing service models define how services are delivered to users and organizations. These models simplify development, deployment, and infrastructure management. The three primary models are Infrastructure as a Service (IaaS), Platform as a Service (PaaS), and Software as a Service (SaaS).
IaaS provides virtualized computing resources over the internet, such as servers, storage, and networking. It's ideal for administrators and developers who want complete control over their environments. Think of Microsoft Azure, Amazon EC2, or Google Compute Engine.
PaaS abstracts much of the infrastructure layer and offers a platform for building and deploying applications. It provides tools, libraries, and development frameworks so developers can focus on code, not servers. Examples include Azure App Services, Heroku, and Google App Engine.
SaaS delivers fully functional software applications via the internet. These are subscription-based and require no setup or installation. Users simply log in and use the software. Think Office 365, Salesforce, and Google Workspace.
Choosing the right model depends on your business needs, control level, and internal IT expertise. Professionals must understand these distinctions to align services with strategy and avoid overspending or underutilizing resources.
Scenario 1: A freelance designer uses Adobe Creative Cloud (SaaS) for editing graphics, Dropbox (SaaS) for file sharing, and occasionally uses AWS Lightsail (IaaS) to test hosting a portfolio site. She doesn’t worry about infrastructure or backend code—everything’s plug-and-play.
Scenario 2: A local nonprofit gets a grant and wants to build a community app. Their developer uses Firebase (PaaS) to spin up the backend in a weekend, deploys it to Google App Engine, and links it to a simple website on Netlify. No servers to patch, no infrastructure to buy—just a complete solution deployed using service models tailored to small teams and fast delivery.
| Model | You Manage | Provider Manages | Best For |
|---|---|---|---|
| IaaS | OS, apps, data, runtime, and most configuration | Physical hardware, networking foundation, virtualization | Maximum control, custom environments, admin-heavy workloads |
| PaaS | Your code, app logic, and data | Servers, runtime, patching, scaling platform | Developers who want to move fast without managing infrastructure |
| SaaS | Mainly usage, settings, and user access | The full application stack | End users and teams that need software immediately |
1. Which service model gives you the most control over infrastructure?
2. Which model best suits developers wanting to deploy code without managing servers?
3. Gmail and Google Drive are examples of what cloud model?
Can you match the following tools to their cloud model? Drag and drop or think it through mentally, then click to reveal answers:
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