IaaS, PaaS, SaaS: the differences between cloud models & examples

What are the IaaS, PaaS and SaaS service models? What are they used for and what is the difference between them? This article will help you find the answers to these questions.

What are the basics of IaaS, SaaS and PaaS?

Before looking into the differences between the main cloud computing models, it’s worth establishing what they all have in common and what the foundation of IaaS, SaaS and PaaS is.

Cloud computing is a way of organizing server and network equipment into a “pool” of resources. The cloud is built using multiple physical servers that work in a single system. This way, the user doesn’t have to work with the parameters of specific servers, but instead uses an abstract set of resources to create virtual machines. Just like a physical server, a VM has a CPU, RAM, storage etc. However, the configuration of each VM is not limited by the physical hardware on one machine. For example, you can increase the amount of RAM or turn off CPU cores at any given moment. This is possible because virtual machines use the resources of multiple physical servers at the same time.

Clouds are used for a variety of corporate tasks, such as deploying e-commerce projects, data bases, ERPs, mail servers etc. In other words, the cloud is a virtual IT infrastructure which can be used to deploy any corporate systems and applications. To learn more about the basics of cloud architecture, read our article in the SIM-Networks blog.

Why do companies choose cloud solutions? Here’s a couple of reasons:

• high fault tolerance thanks to virtualization, redundancy and distributed data storage;
• no need to hire administrators, update software or hardware – this is the provider’s responsibility;
• instant scaling through upgrading virtual resources;
• various access rights levels for users;
• comprehensive services and support.

IaaS, PaaS, SaaS and XaaS are cloud service models; the difference between them lies in the levels of the tasks they solve. The IaaS model provides the client with the computing resources of the cloud; this infrastructure is used to deploy software solutions. PaaS is a model which includes cloud resources and pre-installed tools for various tasks. SaaS users get a full solution, which only needs to be applied; it’s likely that you’ve encountered SaaS services in your everyday life. All of these models can be broadly defined as XaaS, meaning «Anything-as-a-Service».

Differentiating between cloud service models is the key to understanding what separates services that are often called just «clouds ». For example, we, SIM-Networks, offer SIM-Cloud, an IaaS platform for corporate systems. This platform cannot be directly compared to something like Google Drive, even though both of these products are examples of cloud services. Let’s look into these differences in more detail.

What is IaaS? (Infrastructure-as-a-Service)

IaaS (Infrastructure-as-a-Service) is a cloud service model which includes all the basics: server infrastructure, network equipment, storage, etc. Instead of maintaining your own IT infrastructure, you rent a cloud while the provider supports it.

The main benefits of IaaS:

• less spending, as all maintenance costs are the provider’s responsibility;
• the data is located in the provider’s data center, where it’s protected by physical and digital security systems;
• simple scaling that follows the company’s growth.

IaaS is the resource base for a company’s services. The product that IaaS providers offer is a set of computing resources and the tools to manage them. IaaS is used to deploy individual apps, as well as the company’s entire stack of IT instruments: ERP systems, terminal servers, remote offices, data bases etc.

IaaS management and monitoring is carried out through a virtual interface. It allows you to adjust the configuration, add software and additional services offered by the provider.

If a project requires additional resources, all you have to do is add them in the dashboard. For example, you can expand the storage or choose another CPU & RAM combination. If the company is not using all cloud resources, it is just as simple to turn off the ones you don’t need and pay less. All maintenance and support costs are the responsibility of the provider. The company does not need to set up its own data center, pay for electricity or cooling systems etc. This way, IaaS rental allows clients to spend less money and time on IT.

Learn more about the advantages of cloud solutions for corporate clients in various industries in «Do businesses need the cloud?»

The choice of an IaaS solution must be approached from an informed position. When choosing a cloud for your business, take these factors into account:

• Does the provider use redundant components for fault-tolerance?
• How is data protection organized?
• Is the provider’s data center Tier III or higher?
• What guarantees are included in the provider’s SLA?
• Is the tech support service available 24/7?
• What additional XaaS services does the provider offer?

Learn more about the factors of choosing an IaaS cloud; get acquainted with a comparison of SIM-Cloud with Amazon Web Services

XaaS («Anything-as-a-Service») refers to various cloud services. The «X» in the abbreviation is a variable, meaning that this term can refer to any service. In the context of cloud infrastructure, XaaS often refers to additional services meant for use with IaaS. BaaS («Backup-as-a-Service»), automatic reserve copying in the cloud, is a common example of XaaS. The abbreviations used for XaaS services may have different meaning based on the providers and the context. «MaaS» can stand for both «Mobility-as-a-Service» and «Malware-as-a-Service.

What is PaaS? (Platform-as-a-Service)?

PaaS (Platform-as-a-Service) is a service model which provides the client with an preconfigured environment for developing and deploying applications. PaaS examples include email servers, data base management systems, web-servres, development and testing platforms, backup servers etc.

The benefits of PaaS solutions:

• PaaS providers are responsible for any updates and fixes for the software;
• the client doesn’t need to invest in hardware or software – the provider offers the full platform for rent;
• flexibility during deployment: the infrastructure is fully controlled by the provider.

PaaS clients cannot manage the infrastructure used for the software solution. This means that the user cannot turn off surplus resources or add more. The difference between IaaS and PaaS lies in the fact that Platform-as-a-Service provides you with a computing platform and stack of solutions, but you cannot adjust the configuration. Standardized development toolkits are a good reason to pick PaaS. This can significantly improve the efficiency of a team working on the same project.

PaaS (Platform-as-a-Service) examples: Google App Engine, VMWare Cloud Foundry, IBM Bluemix и др.

In the case of IaaS, the computing power of the cloud itself is the product; instead, PaaS uses these resources to solve specific tasks. In other words, you reach out to an IaaS provider to deploy your company’s site, ERP, CRM, data base and other tools. You reach out to a PaaS provider to develop an app, analyze data and more.

What is SaaS? (Software-as-a-Service)?

SaaS (Software-as-a-Service) is a model that provides an application deployed on the provider’s infrastructure. SaaS is a common model that you’ve likely encountered in your everyday life. Typical SaaS clients include end-users of email services, streaming services, small-scale cloud storage, messaging apps etc. Social networks are provided using the SaaS model.

Corporate SaaS clients use apps for video conferencing, ERP and CRM systems, project and time management apps, email services etc. You’ve likely heard of these SaaS (Software-as-a-Service) examples before: Gmail, Jira, WordPress, Citrix etc.

SaaS is a great choice if the provider’s services solve your business tasks; all you have to do is apply a ready-made solution. This model doesn’t require you to work with cloud resources directly or to develop products on your own. In other words, a system administrator works with IaaS, a developer works with PaaS and a regular user works with SaaS.

How do I choose a cloud service model?

The choice of a cloud service model isn’t a difficult one if you have a full understanding of your company’s needs and capabilities.

IaaS is a solution for deploying apps and systems from scratch, which is why it is most often used by corporate clients. Startups and small to medium businesses often choose IaaS because of its relatively low price and quick scaling that can match the company’s growth.

PaaS gives you the resources of the cloud and a set of development tools. The preconfigured platform is a convenient solution if the company needs to solve a certain task for the project, and the provider has all the necessary instruments.

Finally, SaaS is a ready-made product developed, deployed and supported by the provider. These solutions are used by both individual clients and companies. The SaaS model includes messaging apps, CRM systems and other software.

The choice of a service model is a question of whether this software solves the company’s tasks. For example, it’s hard to imagine a modern business that decides to develop its own tool for internal communication; SaaS products such as MS Teams have already solved this problem. PaaS products are good for app development without having to manage the underlying resource base in case of temporary projects. However, IaaS is the basis of a company’s IT toolkit, since no company can be entirely dependent on PaaS or SaaS products. The operational demands of each business are unique, and the IaaS model offers the most control over resources and software that support the key processes of the company.

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