Understanding SaaS, PaaS & IaaS

What's the difference between SaaS, PaaS and IaaS?

Cloud computing:
the difference between
PaaS and IaaS?



Posted by Ludovic Dessemon on 2019:06:21 17:59:36

Understanding the various cloud services is key to making informed decisions related to cloud migration. In this article we will break down the 3 main cloud models: Software as a Service (SaaS) , Platform as a Service (PaaS) and Infrastructure as a Servic


Understanding the various cloud services is key to making informed decisions related to cloud migration. In this article we will break down the 3 main cloud models: Software as a Service (SaaS) , Platform as a Service (PaaS) and Infrastructure as a Service (IaaS) and explain the advantages and concerns related to each.

Type of service Example of service Example of providers

ERP, Email, Marketing, File sharing

Oracle ERP Cloud, Salesforce, Office 365, Slack, Google G-Suite




Database, Chatbot, Mobile, Integration, NoSQL, Java, DevOps, BigData, ...


Oracle Cloud, Heroku, Google Cloud, AWS, Azure, IBM


Virtual machines, Storing, Networks, DNS, Kubernetes, VPN, ...


Oracle Cloud, AWS, Azur, Google Cloud, DigitalOcean, Rackspace




At the most basic level, software as a service is an application hosted on the cloud available to customers over the internet, typically on a subscription basis. Whereas a typical software would be downloaded and run locally, SaaS is hosted by a provider. Examples of SaaS are Salesforce Office 365, Slack & DropBox.

SaaS is the most common cloud deployment with the most obvious advantage being that IT teams don’t need to install and download programs on each workstation and the updates are done automatically.

SaaS allows you to reinvent your business, processes and experiences. SaaS applications offer you the speed and innovation of cloud software in a complete, secure and connected cloud suite.


Advantages Centralized management, accessible from the Internet, no maintenance (hardware and software). No licenses but a cost per use.

Limits & potential concerns


Integration with existing applications and services can be a major concern if these applications are not designed to follow open integration standards.

Data Security

Since a SaaS application must meet the majority of customer needs, customization features are very limited. And this standardization forces customers to check the features offered before engaging with a particular supplier because it can then be difficult to switch to a new supplier. Customers may need to redefine their data security and governance model to adapt to the functionality of the SaaS service.





Platform as a Service enables developers, IT professionals and business leaders to accelerate innovation, increase productivity and reduce costs with a comprehensive set of solutions to develop, extend, connect, secure and mobilize your business applications and obtain actionable information.

Technically speaking, PaaS consists of 3 components: the software your application runs on, the deployment machinery and the user interface. Because it is built on virtualization technology, it offers the flexibility to scale up or down based on the needs of your organization.

As illustrated above, using PaaS offers many real organizational advantages. There are however some concerns across all cloud services namely security, integration of on-prem and cloud data and vendor lock-in among others. As a managed services partner, RENAPS’ role is to provide leadership, expertise and advice to navigate these potential issues as well as hands on expertise in working within PaaS environments.


PaaS allows companies to access innovative services that it would be difficult, if not impossible, to use "on-premise" such as: Blockchain, services with Artificial Intelligence, services to develop without coding (Citizen Developer), etc.

PaaS is a model between SaaS (where the provider manages all layers, from infrastructure to application) and IaaS (where the provider manages the datacenter, its security, the different hardware such as physical servers, routers, storage bays, etc.). In PaaS mode, the customer manages software platforms such as databases and application servers. The servers, networks and storage used by these platforms are managed by the supplier.


  • Makes application development and deployment simple and cost-effective
  • Scalable
  • Highly available
  • Ability to create complex applications without the need to maintain the software
  • Significantly reduces the amount of coding
  • Allows easy migration to a hybrid model
  • Virtualization technology, resources can easily be increased or reduced as needed.
  • Wide range of services to support the development, testing and deployment of applications.
  • Many users can access the same development application

Limits & potential concerns


The PaaS model offers real organizational benefits. However, there are some concerns with these cloud services including: security, on-site data and cloud data integration, and vendor engagement. As a managed services partner, RENAPS' role is to provide mentoring, expertise and guidance to address these issues - security, vendor and integration, as well as practical expertise in PaaS environments.




IaaaS is a comprehensive offering of integrated infrastructure services available on a subscription basis that enables all types of tasks to be performed in a business-specific cloud that is managed, hosted and supported by the provider.

The flexibility of IaaS is a real differentiator. You can "consume" according to your needs. In a world where margins are declining and volatility is increasing, the main advantages of IaaS are agility, scalability, cost reduction and control over your infrastructure.

Organizations using IaaS are responsible for application, data, execution, middleware and OS management.


  • It is the most flexible cloud computing model
  • Easily enables automated deployment of storage, networking, servers and processing power through multiple tools (web console, APIs, command line, scripts)
  • Services provisioned according to needs
  • Gives customers complete control over their infrastructure
  • Can extend an on-premise infrastructure to regions where the customer does not have data centers, all within minutes.
  • The cost varies according to consumption
  • Services are highly scalable
  • Provides complete control of the infrastructure to organizations
  • Dynamic and flexible

Limits & potential concerns



Security and lack of internal resources can be a concern when using IaaS. As a managed services partner, RENAPS has the tools, processes and resources to ensure the safe and efficient deployment and maintenance of IaaS.



Pricing of cloud services depends largely on the provider. 

Most providers offer a no-obligation pay-per-use model, based on a public rate and metrics specific to cloud services (per CPU, Go, Environment,..., per hour, minute or second). It is also possible to reduce costs by choosing a commitment for one year or more, in order to obtain better pricing conditions



Migration to the Cloud may seem like a huge undertaking, we have illustrated that there are many different options for moving to the Cloud and many different cloud services to choose from depending on your business needs and objectives. 

The geolocation of cloud services can also be a determining criterion in your choice.

The recent announcement of a Cloud partnership between Azure and Oracle now allows customers to seamlessly connect Azure services, such as Analytics and AI, to Oracle Cloud services, such as Autonomous Database. 

Our approach towards cloud service providers is agnostic . RENAPS can help you choose the right cloud computing provider, migrate to the cloud, secure your cloud operations and develop cloud applications regardless of which provider you select.

Posted by Ludovic Dessemon on 2019:06:21 17:59:36

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