Do You Know the 3 Key Differences Between SaaS, PaaS, and IaaS

SaaS Management

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Vendr Team
Published on
December 13, 2021
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If you work in a modern office or use a computer on a daily basis, chances are you use cloud service software that helps you conduct business. Cloud services provide easy access to business tools with only needing a personal computing device and an internet connection. Some examples include Google Docs, Slack, and Trello.

Most of us office dwellers use software as a service (SaaS) in our everyday lives. And if you work in IT or application development, you probably use infrastructure as a service (IaaS) and platform as a service (PaaS), too. The as-a-service model has become ubiquitous.

In this guide, we will explain:

  • Major differences between SaaS, PaaS, and IaaS
  • Key features of each model
  • Main advantages of each model
  • When it’s suitable to use each one

What does as-a-service mean?

Cloud computing models operate as a service, meaning the service provider owns and manages the IT assets while you, the customer, pays to use them on a pay-as-you-go or subscription basis. Then, you access the service via the internet.

For example, say you need a software management platform. You could have a team of developers create one, you could purchase one, or you could rent one. Renting a software management platform as a service might be the quickest and most economical choice in this case.

3 key differences between SaaS, PaaS, and IaaS

SaaS, PaaS, and IaaS are different yet interconnected. Depending on your needs, organizations can use them independently or concurrently.

Think of your organization’s technology needs as layers:

  1. The top layer is the software layer, and it’s made up of your applications and data.
  2. The middle platform layer consists of your middleware, runtime, and operating system. This middle layer is everything you need to operate your applications in the top layer.
  3. The foundation is the infrastructure layer, consisting of your servers, networking, virtualization, and storage.

The main differences between SaaS, PaaS, and IaaS come from which layers you choose to manage yourself versus which a service provider operates. For instance, say your company already has an IT infrastructure. In this case, you might only subscribe to SaaS and PaaS solutions.

All service models offer the benefit of flexing with your workload. Also, you can use one, two, or all three models at once, depending on your specific sets of needs.

SaaS solutions

With a SaaS solution, you allow a third-party vendor to manage all layers, including applications and data. SaaS is the most widely known model and is sometimes called cloud application services because of this arrangement.

Examples of SaaS solutions

  • Dropbox
  • Adobe Creative Cloud
  • Salesforce
  • Canva

PaaS solutions

With a PaaS solution, you pay for a cloud service to manage your infrastructure and platform needs—development tools and operating system— but build and manage your own applications. These solutions are popular with DevOps and SaaSOps teams.

Examples of PaaS solutions

  • AWS Elastic Beanstalk
  • Google App Engine
  • ​Heroku
  • OpenShift

IaaS solutions

With an IaaS, a cloud provider manages the IT infrastructure (data center, storage, security, servers, and networking) while you manage the platform and software through a virtual machine (VM). The VM is hosted by shared physical hardware or bare metal servers on dedicated, unshared, and physical hardware.

Examples of IaaS solutions

  • Amazon Web Services (AWS)
  • Google Compute Engine (Google Cloud)
  • IBM Cloud
  • Microsoft Azure


You manage your on-premises infrastructure, platform, and software without a cloud provider. In other words, your organization has built and maintains the IT infrastructure and runs platforms and software altogether, giving access to users through a private network.

Note: Although an on-premise system isn’t an as-a-service option, we’ve added it here for perspective and because it can be used in a hybrid cloud scenario.

Overall, SaaS gives end users the least to manage but also the least control. PaaS provides mid-level control and management. In contrast, IaaS provides the client with complete control and the most responsibility.

What are the key features of SaaS?

At this point of the information age, pretty much anyone who uses a computer or smartphone is a SaaS customer. In a SaaS model, the vendor oversees all the hardware and software, so all you need to do is subscribe to use the application.

Some key features of SaaS include:

  • Centrally located management hosted on a remote server
  • Internet accessibility
  • Automatic updates
  • Workload scalability

What are the advantages of SaaS?

SaaS is the easiest-to-use option out of SaaS, PaaS, and IaaS. The best advantage is that to begin using it, all you have to do is create an account and pay for the service, using only a web browser or device app.

Further, the monthly or annual subscription model helps organizations avoid hidden fees. This model prevents underutilized software or overpaying for using more than expected. Plus, there’s little to no financial risk because most vendors offer a free trial or allow cancellation at any time.

In addition, SaaS frees up IT employees to focus on higher-order aspects of their roles. They no longer have to waste time downloading and installing applications on computers one by one because multiple users can access the same solution through the internet. Plus, the vendors manage upgrades, backups, and most issues that could arise.

When is SaaS appropriate for you?

SaaS is usually appropriate when you want easy access to applications with minimal oversight on your part, such as apps for communication, collaboration, or content creation. Other situations in which SaaS might be the best option includes:

  • Short-term projects: If you’re looking to complete a specific task in the next three months or less, then the flexibility of SaaS is a good fit.
  • Small businesses and startups: Using SaaS solutions will give you quick tools with the flexibility to help you grow and the affordability to keep you on budget.
  • Customization not needed: SaaS solutions work best for organizations that can use the tool “off the rack,” so to speak.

What are the key features of PaaS?

Platform as a service, also known as cloud platform services, has developers primarily as customers. In this as-a-service model, the customer manages their own data and applications while the cloud provider oversees the backend.

Some key features of PaaS include:

  • Provides developers with a secure platform (as opposed to only software)
  • Delivered via the web
  • Allows businesses to design and create middleware
  • Is scalable

What are the advantages of PaaS?

A PaaS model has several benefits for organizations developing software. When the platform is provided as-a-service, developers can significantly speed up a product’s time to market because developers need to write less code when using a PaaS. Further, developers are free to customize apps without maintaining software.

PaaS can also save organizations money and help teams streamline workflows. Like SaaS, PaaS tools are simple to access and start using.

When is PaaS appropriate?

Developers use PaaS when they need an online platform for application development. Although the delivery model is similar to SaaS, customers access an online platform for software creation instead. Likewise, software developers and engineers use PaaS when they need ready-to-go tools without dealing with elements like storage, infrastructure, and operating systems.

What are the key features of IaaS?

Companies may opt for IaaS instead of on-premises hardware, which is why IaaS is synonymous with cloud infrastructure services. These customers use the internet to access hardware on a pay-as-you-go or subscription basis.

IaaS was the first as-a-service offering from the major cloud service providers like Microsoft Azure and Amazon Web Services. As a result, these services paved the way for future as-a-service offerings.

Some IaaS key features include:

  • High scalability
  • On-demand capacity
  • Automated compute resources
  • Cloud-based alternative to on-premises data centers

What are the advantages of IaaS?

IaaS providers allow users to have the same benefits as on-premise data centers without the upfront costs and overhead. In other words, IaaS eliminates the costly need to build, manage, or maintain a labor-intensive traditional data center.

Customers have the freedom to configure and use their cloud-hosted computing infrastructure as they need with this model. Plus, this flexibility eliminates wasted resources and allows for easy scalability.

When is IaaS appropriate?

IT or system administrators use IaaS because this solution gives all the power of a data center, its platforms, and software without a huge price tag. Nowhere can they meet their compute, network, and storage resource needs for less. In addition, customers can access and configure IaaS accounts as they see fit without the burden of managing on-premises data centers.

Moreover, the flexible pay-as-you-go model makes it cost-effective for companies of all sizes. This lets startups get to business with less initial overhead and established organizations maintain control of their infrastructure and applications while saving money. Plus, growing companies can change and scale their hardware and software to match their constantly changing needs.

Other as-a-service models

SaaS, PaaS, and IaaS are the most common cloud service models, but they aren’t the only ones. While we won’t get into the weeds with these alternative models, here is a list of others you might be interested in learning more about:

  • XaaS: Anything as a service
  • FaaS: Function as a service
  • CaaS: Containers as a service
  • MaaS: Mobility as a service

How Vendr's complete IT platform can help your SaaS, PaaS, and IaaS management

As-a-service options can allow your organization the flexibility it needs to grow while reducing your spend. Still, it’s up to you to manage your technology stack effectively and responsibly to avoid SaaS sprawl, a costly consequence of poor application management.

Learn more about how Vendr can automate, organize, and secure every aspect of your IT stack.

Vendr Team
Vendr's team of SaaS and negotiation experts provide their curated insights into the latest trends in software, tool capabilities, and modern procurement strategies.

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