Today, there are three main types of cloud computing services: Infrastructure as a Service (IaaS), Platform as a Service (PaaS) and Software as a Service (SaaS). Each model offers organisations a different level of control and convenience, from simply renting servers to using fully managed applications. In this post, we explain what each model is, assess their similarities and differences and discuss the advantages they provide. We also look at the benefits of managed hosting, where providers handle routine administration on behalf of businesses.
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What are cloud service models?
Cloud service models describe the different ways that businesses can rent cloud technology and the different levels of responsibility for managing it. In other words, how much of the IT stack is managed by you and how much by the provider.
- IaaS provides virtual servers and storage that your business configures and manages.?
- PaaS provides you with a ready-made environment for building, testing and running applications, including infrastructure and software.
- SaaS offers complete application solutions, such as email or CRM, which are delivered online via a browser or app.
Many organisations use a mix of these services. For instance, a retailer might run its online store on IaaS, use PaaS to develop new features and choose a SaaS provider for its office software. While this max may seem complex, opting for a managed solution, where monitoring, patching, security and performance are handled by the provider, can significantly reduce the burden on IT teams.
Infrastructure as a Service (IaaS)
IaaS essentially means that you rent a cloud server. This provides your business with on-demand compute, storage and networking resources. Typically, businesses are responsible for managing the operating systems, databases and apps, while the provider maintains the hardware. With managed IaaS, however, the provider will also take care of OS updates, monitoring and backups.
Advantages:
- Full control over systems and applications.
- Scalable resources that adapt to demand.
- No upfront spend on hardware.
- Managed services add resilience and support.
Use cases: Hosting busy websites, running customised databases, or setting up disaster recovery environments. Managed IaaS is particularly useful for businesses that need control but lack the resources, expertise or workforce capacity to manage the infrastructure in-house.
Not adopted cloud hosting yet? Read: 10 Reasons to Migrate to the Cloud
Platform as a Service (PaaS)
PaaS, which is primarily used for software development, is a combination of IaaS, together with the operating systems, middleware and development tools. This set-up enables developers to focus on writing and deploying software while the provider manages the platform. With a managed PaaS solution, the provider also takes care of scaling, patching and monitoring.
Advantages:
- Provides preconfigured environments and helps speed up development.
- Comes with built-in scaling and load balancing.
- Managed services help reduce operational burden on IT teams.
Use cases: Start-ups wanting to launch new apps quickly, teams running rapid development cycles, or businesses building SaaS products without wanting to maintain infrastructure. Aside from app development, PaaS has also been used by DevOps teams to streamline workflows and by data scientists to process large datasets.
Make the most of your cloud spending, read: How to Achieve Cost Optimisation through Managed Cloud Services?
Software as a Service (SaaS)
SaaS provides businesses with cloud-based applications, paid for by subscription and accessed via a browser or app. Rather than users having to install large applications on individual machines, they simply sign in. With SaaS, the provider manages everything, including infrastructure, updates and security.
Examples: Google Workspace, Microsoft 365, Adobe Creative Cloud, Salesforce, Zoom, Slack.
Advantages:
- Accessible from any device with an internet connection.
- Automatic updates and patching.
- Consistent user experience across all accounts.
- Predictable subscription costs.
Use cases: Productivity and collaboration tools, CRM platforms, HR systems or finance applications. SaaS is the simplest of the cloud models as it offers immediate access to industry-leading software without the need for in-house management.
Comparison of IaaS, PaaS and SaaS
Considerations when choosing
When choosing any cloud service, organisations should consider the following:
- Portability: Understand how easily workloads can be moved between providers.
- Integration: Ensure chosen services connect smoothly with your existing systems.
- Skills and support: IaaS needs more technical input than SaaS, though managed hosting and 24/7 technical support can reduce the expertise required.
- Compliance: Check data location and whether the provider meets GDPR or sector regulations.
For more information about compliance, read: How UK Data Sovereignty Impacts Your Cloud Strategy in 2025
Making the choice
With regard to which cloud service model to use, IaaS is the best option if your business needs control over its systems; PaaS is ideal for creating a managed environment to build apps; and SaaS is the simple solution for deploying ready-to-use, cloud-based software. Today, many organisations make use of all three models.
Key takeaways
- IaaS provides the greatest flexibility but requires more technical input.
- PaaS simplifies development by offering a managed environment.
- SaaS offers ready-to-use applications with minimal management.
- Managed hosting reduces complexity and burden across all three models.
- Most organisations can benefit from combining these models for different needs.
Conclusion
IaaS, PaaS and SaaS are the three primary models of cloud computing. Choice is not a matter of either or; it is about deploying the right model for the right purpose. A managed hosting solution, meanwhile, makes adoption easier, as providers take care of security, monitoring and maintenance, enabling you to focus on your business goals.
Looking for an enterprise-class managed IaaS solution? An HM Government G-Cloud supplier, eukhost’s UK-based cloud servers are designed to deliver the uptime, performance, scalability, security and support organisations need to run mission-critical applications. For more information, visit our Managed Cloud Servers page.
