SaaS, PaaS, IaaS: what does it mean?

  • 11 February 2021
  • Reading time: 8 min
  • Hosting

When looking for information on the cloud, you will often come across terms like IaaS, PaaS and SaaS. For IT professionals who use them on a daily basis, these abbreviations are quite common, but newbies will probably not be able to make much sense of them.

Luckily, you have come to the right place, as we are going to explain the difference between these three concepts. Just a hint: these are three services that are connected with cloud computing. That is working in the cloud, with as little as possible on your own computer.

The "as a Service" model

The first thing to notice is that each of these words ends in "aaS", which stands for "as a Service". So they are all 'services', more specifically cloud services.

This means that you do not have to buy anything yourself. Instead, you simply 'rent' the services. This concept is as old as the hills, of course: if you have a cleaner, he or she is obviously not your property, but provides a 'cleaning service as a service'. But then we are obviously not talking about cloud services 😉.

The big difference between Iaas, Paas and Saas lies in the scope of the cloud solution. How much do you have to provide yourself, and how much input does your 'as a Service' partner have?

Your cloud consists of various components: infrastructure (servers, cables, network, etc.), operating system and security software (Windows, Linux, antivirus solutions, etc.) and, finally, ready-to-use software packages that you can use as an end customer.


This results in the three segments Iaas, Paas and Saas: infrastructure, platform and software. SaaS is the most common cloud service, encompassing the other two cloud services. Let us first consider the lowest layer: Infrastructure as a Service.

What is Infrastructure as a Service (IaaS)?

IaaS stands for Infrastructure as a Service. At the very basis of your cloud services is the infrastructure. And you can buy this as a service: this is the IaaS model.

This solution ensures that you get (from a good service provider) reliable equipment that is always available. You then configure your operating system and other software yourself.

In other words, you outsource the physical part of your cloud: you rent 'empty server space' from an external provider.


Companies that move to the cloud often choose IaaS. This means that they outsource their entire ICT system, including storage and connectivity, to an external service provider (such as Combell). This is safer and easier than keeping your own servers 'on premise'.

Instead of purchasing servers, storage, firewalls and network equipment, a company rents everything as a service, and the entire setup is in an external data centre.

But make no mistake: even though your infrastructure is no longer located in your own office, IaaS still allows you to decide what happens with it. For example, you are entirely free to choose the operating system and the software that will be installed on your servers.

IaaS is also often called an 'unmanaged' cloud: your service provider guarantees the infrastructure, but does not provide software management. Fortunately, Combell offers a solution for this 😉.

Managed IaaS with Combell

With IaaS, Combell also provides managed services. Because although many companies see the advantage of Infrastructure as a Service, they still struggle with the fact that this rented infrastructure must be managed by their own system administrators or an IT service provider.

What Combell does is remove that last obstacle: with our managed cloud, we manage your rented infrastructure and take care of the security, privacy, monitoring and backups of your system.

Combell provides rock-solid guarantees for maximum uptime, but also ensures business continuity and disaster recovery. And as an added bonus, we give you expert advice on every project you want to start.

We also get you started with DevOps, so that your developers can build new applications or websites that are even more in tune with your infrastructure. So you no longer have to worry about uptime, as we take care of everything for you.

Moreover, with your managed cloud solution, Combell offers excellent SLAs, which ensure fast response times or the monitoring of your hardware and software.

With Combell, you can purchase both unmanaged and managed IaaS, depending on what best suits your needs!

The benefits of IaaS

When you go for IaaS, you mainly go for peace of mind, but the benefits go beyond that.

Clear costs: You will not be faced with unexpected investments: maintenance costs and investments are the responsibility of your service partner!
Guarantees from your provider. Your service provider ensures that your infrastructure continues to run smoothly. If you go for managed IaaS, you even obtain guarantees that the performance of your server will be monitored, and these provisions will be laid down in a Service Level Agreements. In addition, the service provider guarantees that it will take action (quickly) in the event of problems. And if it fails to do so, it will have to pay substantial compensation.
Control: You can install your own software on it and experiment, without your service provider having to step in every time.
No more worries: The daily management of your infrastructure is in the hands of your provider. With managed Iaas, you can also stop worrying about system and security updates.
Scalability: When your business grows, you can request more capacity from your provider in no time.

The drawbacks of IaaS

The disadvantages of IaaS apply mainly to unmanaged IaaS.

Relatively expensive. You rent your entire infrastructure, and that includes all the costs related to usage. Think of it as a comparison between taking a taxi sporadically and renting a car for a whole month: the rent will obviously be more expensive – unless you take the taxi very often!
Privacy is sometimes a sore point. With non-local IaaS providers (especially those from outside Europe), you should also ask yourself questions about privacy compliance. Local providers such as Combell are in any case GDPR compliant.
Responsibility: You have to take care of your own security and backups, as well as maintain the software that runs on your infrastructure. When you opt for managed services, your provider takes care of your security, software and backups, making your responsibilities much more limited.

Who uses IaaS?

You can think of IaaS as your own server, but in a different location. It is ideal for companies that want to move their entire on-premise servers to the cloud.

What is Platform as a Service (PaaS)?

PaaS stands for Platform as a Service. With this, in addition to the physical part of your cloud, you also outsource the management of your operating systems.

This means you can develop software in the cloud and then offer it to others as SaaS. PaaS is thus aimed almost exclusively at programmers: you get a comprehensive development platform on which you can develop your own applications and make them available to the public.


The benefits of PaaS

The benefits of Platform as a Service are pretty much the same as those of IaaS, but with even more peace of mind.

Worry-free. Thanks to PaaS, developers do not have to worry about their system or its security.
Reduced start-up costs and faster launch. When you want to develop an application, you do not have to purchase the entire infrastructure.
Efficiency. As a developer, you can focus on developing your own software or application, without having to deal with your infrastructure problems.
Flexibility and scalability. The computing power of your system is dependent on what you actually want to do with it, and not the other way around. Your possibilities are therefore not limited by your infrastructure!

The drawbacks of PaaS

There is one major disadvantage to PaaS – although this is often not as great as the disadvantages of developing an application on your own systems.

'Vendor lock-in'. When you develop an application with a certain PaaS provider, you are often tied to it. This is because each platform has its own standards, which means that applications cannot simply be transferred from one platform to another.

Who uses PaaS?

PaaS is ideal for people who develop websites or applications and who do not want to lose any sleep over the security and management of their rented infrastructure. It allows these developers to easily develop SaaS solutions on the rented platform.

What is Software as a Service (SaaS)?

The most common form of cloud computing is SaaS: Software as a Service. When you choose SaaS, you no longer purchase and install software locally on your computer. Instead, you replace that software with software that is offered as an online service.

As an end user, Saas allows you to enjoy a very comfortable working environment: you can start using the software right away without any technical knowledge! The provider bears all responsibility for ensuring that the product works properly. SaaS also includes IaaS and PaaS, but more on that later.

An example of Software as a Service is Microsoft Office: in the past, you had to buy a new CD-ROM version of the Office suite every few years if you wanted to be able to benefit from the latest features. Now, Microsoft mainly offers the SaaS version of Office (in the Microsoft 365 package).

Microsoft 365 apps

The main advantage of SaaS is that customers no longer have to buy a software licence. Instead, they pay a monthly or annual subscription for the service provided, often based on the number of users. And this also includes all updates.

Examples of SaaS

Microsoft 365 (Office 365), with Teams, Word, Excel, PowerPoint, etc.
A CRM system such as Teamleader
Adobe Photoshop and related software (in the Creative Cloud)
Slack, to share information at work
GMail, online mailing software
SiteBuilder, to create your own website.

Combell itself also supports SaaS solutions. That is why we are proud of customers who have developed their own Software as a Service solutions. These include:

ScriptBook: SaaS that predicts whether a Hollywood script has a chance of becoming a blockbuster.
Yesplan enables cultural institutions to manage their activities, staff and equipment through one convenient SaaS tool.
InTouch: Mobility software that helps municipalities, for example, to issue digital resident cards.

The benefits of SaaS

You can always use the latest version. Updates for the software are often installed automatically, meaning that you do not have to constantly update it yourself or buy a new version.
No large initial investment. You pay a periodic subscription fee, so you do not have to spend a fortune on the software.
Scalable. When you take on new employees, you can create an account for your new colleague in the blink of an eye. Likewise, when you decide to downsize your business a little, accounts can be cancelled just as easily.

The drawbacks of SaaS

Unfortunately, every advantage has its disadvantage:

The cost price in the long run. If you consider the total period of use, you will notice that the costs can be prohibitive. Just think of the self-employed graphic designer who uses an Adobe package costing EUR 70 per month for 40 years. That amounts to around €33,000 over his/her entire career. Ouch!
Availability. When your data is in the cloud, you are completely dependent on your own connection to that cloud. In other words: no Internet means no SaaS. Although companies can avoid this situation by having 'dedicated connectivity' and their own company network.
Security. You do not always know where your data are stored, which means you are somewhat dependent on what your SaaS provider does.

Who uses SaaS?

SaaS is so widespread that almost everyone uses SaaS. Just think of your Outlook or Gmail account, or Windows 365.

Combell as a cloud partner

Whether you are looking for an IaaS solution to move to the cloud or, if you are a developer with PaaS, you want a platform to develop your application or SaaS, Combell will be happy to help you.

We always focus on three pillars: security, performance and accessibility. This way, you can work confidently, on a solid infrastructure, whenever you want!