Susanne Tedrick
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Cloud Service Models Explained
Cloud, Tech

Cloud Service Models Explained

IaaS PaaS SaaS

About 81% of all enterprises already have a multi-cloud strategy laid out or in the works, meaning that they are using more than one cloud service provider to accomplish their goals. In fact, Platform-as-a-Service (PaaS) grew in adoption to 56% by 2020. Despite the increased popularity of these services, many people don’t understand the difference between the options available, and what it ultimately means for them.

In this post, we will examine the differences and benefits amongst these cloud service models, and ultimately, what makes sense for your needs.

Before we start, a cloud service model is essentially how services on the cloud are delivered to you. Each service model has implications to you on what you can control, as well as what aspect that both you and your respective cloud service provider is responsible for installing, maintaining, fixing, etc,


IaaS stands for Infrastructure-as-a-Service. This cloud service model delivers infrastructure as on-demand services. Typically, cloud services like storage and networking would fall in this category. With IaaS, you won’t own the platform yourself. You can, however, make changes as needed to the infrastructure. 

IaaS services are managed solely by your cloud service provider. As the customer, you’ll manage everything else, including:

  • Operating systems
  • Virtual machines and containers
  • Applications built on top of the virtual machines and containers

With IaaS, you won’t have to deploy, configure, or maintain physical equipment.  The benefits of IaaS include:

  • Reduced hardware infrastructure expenses
  • No need to invest in expensive servers, storage, networking resources, etc.
  • Good scalability as your needs grow.

IaaS is not always a perfect solution. There are a few disadvantages. IaaS isn’t always the lowest total cost of ownership; you may find that after careful analysis, it may be cheaper to have physical servers. You may still need an IT team to manage resources. You may also find that you want more control over your infrastructure services (like the physical security of the servers being used to deliver services) that cloud service providers just may not allow.

IaaS costs can also be unpredictable. While it’s easy to scale, you might neglect to put in mechanisms to control your costs. You can work with a cloud service provider to determine the best setup for your needs.


PaaS stands for Platform as a Service. PaaS allows people and businesses to develop their applications and products partially or completely online. You can use it for a vareity of services, like database management or analytics.

Developing applications with PaaS allows for building highly customized applications very quickly, and without having to worry about how data will be served or stored, or scaling to increased needs. Developers also do need to worry about the underlying infrastructure or operating systems, as that is all handled by the cloud service provider..

PaaS gives administrators control over their platform software. You’ll also have control over the applications you’re building within the platform. PaaS cloud services are also ideal if you need to support multiple programming languages in one place. Developers can work on several different projects in one environment.

There are a few disadvantages to consider, though. For example, you’ll only control what you’re building within the platform. If you experience a power outage, you could lose the software. As with IaaS, you could experience unpredictable charges and less customer control and flexibility.


Software as a Service, or SaaS, is the most common type of cloud computing service model utilized by people and businesses today. You can access the applications you need from anywhere in the world. You can run the software through your browser without downloading anything.

SaaS has many advantages – it’s highly scalable and easy to use and manage. You can use SaaS on multiple devices at once. No software downloads and installations are necessary, and it’s relatively easy to scale according to your needs.

One of the biggest downsides of SaaS though is that you lose just about all control over the underlying infrastructure, and application code. When you use SaaS products, they are essentially as-is, and there’s no customization available to end-users. Also, like IaaS and PaaS, if there’s an outage with the cloud service provider, you are pretty much out of luck accessing anything.

The graphic below represents what’s covered by you (in this case, what you’d manage is on the far left as “Customer Managed”) and what would be covered in each model.

Types of Cloud Computing

Which Cloud As A Service Makes Sense For Me?

The choice between IaaS, PaaS and SaaS depends on your unique needs and constraints. While budget is likely a major factor, things like your industry or end users may also play a big role in your decision. For example, many heavily regulated industries, like financial services and energy and utilities, have very specific requirements on how the cloud may be utilized. There may be instances in where you need more control over the integrity and security of your data and infrastructure than one model may allow.

Generally speaking, if you need more control over your applications, consider IaaS. IaaS is best for teams that require virtual machines. It’s flexible and a great way to save time and money. However, you’ll need to maintain your own backups and security.

PaaS is ideal if you plan on building software products. If your developers need extra space, or really want to leverage the benefits of cloud native application development (think containers and microservices), this would be ideal. While most of the major (and more reputable) cloud service providers will not access your data, ultimately you’re at their mercy if there is a breach or outage.

SaaS is ideal if you use out-of-the-box, as-is services and do not require any software customization. For example, you might need SaaS for email, collaboration tools, and customer relationship management (CRM). As with the other models, runaway costs is always an issue, and the overall integrity and security of the software is the provider’s responsible.

Because these services rely on the reliability of the cloud service provider, it’s always incredibly important to research and vet them out before using them, and regardless of the model you choose.