Describe cloud service types
📘Microsoft Certified: Azure Fundamentals (AZ-900)
Microsoft Certified: Azure Fundamentals (AZ-900)
Main Topic: Describe Cloud Service Types
Sub-topic: Describe Software as a Service (SaaS)
This topic is very important for the AZ-900 exam. You must clearly understand what SaaS is, how it works, who manages what, its benefits, and how it compares to other cloud service models.
Let’s explain everything in simple and easy English so that both IT and non-IT students can understand.
1. What is Software as a Service (SaaS)?
Software as a Service (SaaS) is a cloud service model where:
- The cloud provider delivers a complete, ready-to-use application
- The application is accessed over the internet
- Users do not install or maintain the software
- Everything runs in the provider’s cloud infrastructure
In simple words:
SaaS = You use the software, but the cloud provider manages everything behind it.
2. How SaaS Works
With SaaS:
- The application runs in the cloud provider’s data center.
- Users access it through:
- A web browser
- Or a thin client application
- No local installation is required.
- Updates and maintenance are handled by the provider.
For example in IT environments:
- Email systems hosted in the cloud
- Online collaboration platforms
- Cloud-based CRM systems
- Cloud-based HR systems
- Online accounting platforms
The user only logs in and uses the application.
3. Who Manages What in SaaS?
This is very important for the AZ-900 exam.
In SaaS:
The Cloud Provider Manages:
- Physical servers
- Storage
- Networking
- Virtualization
- Operating system
- Middleware
- Runtime
- Application
- Updates and patches
- Security of infrastructure
The Customer (User) Manages:
- User accounts
- Access permissions
- Data entered into the application
- Configuration settings (within the app)
So in SaaS:
The customer has the least responsibility compared to IaaS and PaaS.
4. Key Characteristics of SaaS
You should know these features for the exam:
1. Hosted and Managed by Provider
Everything runs in the provider’s cloud.
2. Accessible Over Internet
Users connect using HTTPS or web-based access.
3. Subscription-Based Pricing
Usually:
- Monthly payment
- Per-user pricing
- Pay-as-you-go model
4. Automatic Updates
The provider:
- Applies patches
- Fixes bugs
- Adds new features
Users do not manually upgrade software.
5. Multi-Tenant Architecture
Multiple customers use the same application instance securely.
This means:
- One application
- Many customers
- Data is isolated between customers
5. Benefits of SaaS
You must understand the advantages clearly.
1. No Installation Required
Users do not install software locally.
2. Lower Upfront Cost
No need to:
- Buy servers
- Buy expensive licenses
- Build data centers
3. Fast Deployment
You can start using the software:
- Immediately after subscription
- No infrastructure setup needed
4. Automatic Scaling
The provider handles:
- Increasing users
- Increasing storage
- Performance improvements
5. Accessibility
Users can access SaaS:
- From anywhere
- From different devices
- As long as internet is available
6. Reduced IT Management
Internal IT teams do not need to:
- Patch servers
- Upgrade software
- Maintain infrastructure
6. Limitations of SaaS
You should also understand the disadvantages.
1. Less Control
You cannot:
- Control the underlying infrastructure
- Customize deeply
- Access the OS or servers
2. Internet Dependency
If internet is down:
- Access to the application is limited or unavailable
3. Limited Customization
Customization depends on what the provider allows.
7. SaaS vs PaaS vs IaaS (Exam Comparison)
This comparison is commonly tested in AZ-900.
| Feature | SaaS | PaaS | IaaS |
|---|---|---|---|
| Application Managed By | Provider | Customer | Customer |
| OS Managed By | Provider | Provider | Customer |
| Infrastructure Managed By | Provider | Provider | Provider |
| Customer Control Level | Lowest | Medium | Highest |
| Target Users | End users | Developers | IT administrators |
Key Point to Remember:
- SaaS → Use the application
- PaaS → Build and deploy applications
- IaaS → Rent infrastructure
8. Examples of SaaS in Microsoft Azure
For AZ-900, you should know Microsoft examples:
Microsoft 365
- Exchange Online
- SharePoint Online
- Teams
These are SaaS because:
- Microsoft manages everything
- Users only access the applications
Dynamics 365
- CRM
- ERP systems
- Business applications
Azure DevOps (partially SaaS-based services)
9. When Organizations Choose SaaS
In IT environments, SaaS is used when:
- The company needs standard business applications
- Quick deployment is required
- There is no need for deep customization
- IT team wants to reduce infrastructure management
- Budget control through subscription model is preferred
10. Security in SaaS
Important for exam:
Even though the provider manages infrastructure security:
- The customer is responsible for:
- Data protection
- User access control
- Identity management
- Strong passwords
- MFA configuration
This follows the Shared Responsibility Model.
In SaaS:
- Provider → Infrastructure security
- Customer → Data and access security
11. Exam Tips for SaaS (AZ-900)
You should remember:
✔ SaaS delivers complete applications
✔ No infrastructure management by customer
✔ Subscription-based pricing
✔ Accessible over internet
✔ Provider handles updates
✔ Least customer responsibility
✔ Multi-tenant model
If a question says:
- “Fully managed application”
- “No need to manage OS”
- “Users access through browser”
- “Cloud-based email solution”
→ The answer is usually SaaS.
12. Simple One-Line Definition for Exam
You can remember this:
Software as a Service (SaaS) is a cloud service model where the cloud provider hosts and manages a complete application, and users access it over the internet without managing infrastructure or platforms.
