Cloud Service Models

What is a Cloud Service Model?

Updated on: October 12, 2026

Author: Ioana Grigorescu, Content Manager

Reviewed by: Meir Amzallag, CEO & Co-Founder

Understand cloud service models like SaaS, PaaS, and IaaS. This guide explains their unique characteristics and how they fit within the cloud computing landscape.

What is a Cloud Service Model?

Cloud service models are the way in which computing services are fulfilled through the internet. Basically, you will rent rather than own the physical hardware and software, which is then accessed through the cloud as a pay-as-you-go service. NIST’s definition, SP 800-145 (September 2011), defines three: software, platform, and infrastructure as a service.

What are the main Cloud Service Models?

The three main cloud service models are:

Software as a Service (SaaS): This service is ready-to-use software accessed through an application via a mobile app or web browser. Examples include Google Workspace, Microsoft 365, and Salesforce.
Platform as a Service (PaaS): Removing the need to manage servers, storage, or operating systems, PaaS is a platform for developers to build, test, deploy, and manage applications. Examples include AWS Elastic Beanstalk, Google App Engine, and Heroku.
Infrastructure as a Service (IaaS): IaaS provides digital services, such as virtual machines, storage, and networks, and is associated with the highest level of infrastructure control when compared to PaaS and SaaS. Examples include AWS EC2, Google Compute Engine, and Microsoft Azure Virtual Machines.

What are the key differences between SaaS, PaaS, and IaaS?

The key differences between SaaS, PaaS, and IaaS are who controls each layer of the stack, who uses it, and how it is billed:

Feature	SaaS	PaaS	IaaS
Control & Management
User Controls	User settings only	Applications and data	Applications, data, runtime, middleware, OS
Provider Controls	Full infrastructure and software stack	Infrastructure and development platform	Physical infrastructure only
Management Complexity	Minimal	Moderate	High
Usage & Implementation
Primary Users	End users	Developers	IT Administrators
Technical Expertise Required	Minimal	Moderate to High	Extensive
Typical Use Cases	Email, CRM, productivity suites	Application development and testing	Virtual machines, data storage, hosting
Business Considerations
Cost Structure	Subscription-based, per user	Usage-based, development-focused	Resource consumption based
Scalability	Limited to application features	Platform-dependent scaling	Highly flexible scaling
Customization Level	Limited to application settings	High within platform constraints	Complete infrastructure control

Why is SaaS Considered a Type of Cloud Computing?

SaaS functions as cloud software, with applications maintained on a provider’s servers and available via the internet; installation and maintenance on user hardware are not typically involved.

How to Choose the Right Cloud Service Model for Your Business

For a good fit, consider the following factors:

Budget: Consider what you are willing to spend, but keep in mind that it ranges from SaaS to IaaS when it comes to the differences in expense.
Business Needs: Think about your unique needs. Do you require a full software application or a development platform?
Control: If this is a factor, consider that IaaS offers the most, while SaaS offers the least.
Technical Expertise: Does your team have the necessary knowledge? SaaS requires the least technical expertise, while IaaS requires the most.

Note:

The service model is a separate choice from the cloud deployment model: NIST pairs its three service models with four deployment models, such as public, private, and hybrid cloud (NIST, 2011).

Conclusion

There are options for all businesses when choosing cloud computing. Once you understand your needs for these services, an informed decision can be made about which you are most aligned with to meet your specific needs.

Key takeaways