Cloud Service Models explained

By admin - 1 July, 2021 - Cloud Back Up

IaaS, PaaS, SaaS. You may have seen these acronyms mentioned when looking at cloud services but what do they mean and how should they affect your decision making when looking at moving your applications or infrastructure to the cloud?

It’s important that you understand the differences between each one of these cloud models so that you know who is responsible for looking after the different elements of your cloud solution. 

Let’s take a look at the following diagram which visualises the different models and their differing levels of responsibility then examine each of the options in further detail below. 

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IaaS – Infrastructure as a Service 

Infrastructure-as-a-Service in simple terms provides your network, storage and computer requirements delivered through the cloud. You will receive access to a quota of hardware resources in the cloud provider’s infrastructure on which you can run virtual machines, applications and route network traffic. 

This is the most flexible cloud computing model in the sense that, operationally, it can work the same as your on-premise servers. It is commonly used for hosting virtual machines, which could be existing domain controllers / file servers / app servers. Existing workloads, including legacy software, can be migrated to the cloud using IaaS with very little disruption as it doesn’t require any large software modifications. The primary consideration is connectivity to the hosting provider. 

With this model, your cloud provider is responsible for providing and supporting their infrastructure and to provide you a resilient platform. Beyond this you are still responsible for what you choose to host on that infrastructure. Any operating systems, data or applications would still need to be maintained and supported the same as if they were on premise. Backups will also have to be considered. 

PaaS – Platform as a Service 

Platform-as-a-Service takes the cloud providers responsibility further and means that you don’t have to look after or be aware of any operating systems or middleware that underpin the platform you are consuming. PaaS solutions are primarily based around hosting software and data. A common example of this would be Microsoft Azure SQL which allows you to host SQL workloads in the cloud without having worry about any database management functions such as managing SQL Server, Patching, Upgrades and Monitoring. These are all owned by the platform and managed for you by Microsoft. You also benefit from virtually infinite scalability on demand.

SaaS – Software as a Service 

Software-as-a-Service gives you an all-encompassing cloud solution where every element up to the software is hosted and managed by the cloud provider. The majority of SaaS applications run directly through your web browser which means they do not require any downloads or client-side software installations. They are commonly billed on a price per user basis. Examples of SaaS solutions would be Dropbox, Office 365 Web Apps, Iplicit ERP and Xero Accounts. Smartphone apps are sometimes developed to access SaaS software. SaaS solutions offer fast implementation without the need to manage infrastructure but do involve you handing over full control of your data to the third-party provider. 

If you have any questions that you need answering on Cloud backup, would like a quote or to trial the Amber Vault Cloud Backup solution, then contact the Amber Vault Team here (hyperlink to be added)


To summarise, each of the above models has its own pros and cons and depending on whether you are transitioning existing workloads to the cloud or perhaps setting up a new business, there is no one-size-fits-all answer as to where to position your company in terms of the solutions available. 

The most effective way to begin the process is to examine the elements of your system individually and consider where these would be best placed to give you the required amount of control of your data and applications whilst still providing a cost effective and scalable solution. 

Offloading as much of the support element as possible to the cloud provider will ensure you are adequately covered, reducing dependency on in house expertise. 

Hybrid cloud solutions where you pick and choose software and services with the best fit for your business are now commonly adopted. This is an agile approach where you end up with a custom solution tailored to your specific needs regardless of where you may be on your cloud journey. 

All solutions benefit from opex billing to reduce costly capital outlays. 

If you have any questions on the above, then please contact the Amber Vault Team. (Hyperlink to be added)