IaaS, PaaS, and SaaS Comparison

Learn about the different services of the cloud (IaaS, PaaS, and SaaS), their advantages, disadvantages, and their differences from each other.

Cloud computing is really popular nowadays due to its enormous benefits. The cloud model is broadly divided into the following three main categories:

  • Infrastructure as a service (IaaS)
  • Platform as a service (PaaS)
  • Software as a service (SaaS)

Let’s get into the detail of each service:


IaaS provides end users with an alternative cloud-based solution compared to an on-premise infrastructure, so they don’t need to worry about purchasing and managing the hardware. Some examples of this service are Azure virtual machines, AWS EC2, and VPN gateways.

Advantages of IaaS

  • It benefits organizations that are experiencing rapid growth but lack capital investment for hardware.

  • It ensures that the data they manage (our information) is safe and secure because IaaS cloud service providers heavily invest in their IT security operations.

  • Scalability and flexibility are essential characteristics of IaaS. With IaaS, our business can scale up and down based on demand.

Disadvantages of IaaS

  • Moving from one IaaS service provider to another can be troublesome.

  • Service-level agreements (SLAs) can be challenging to understand.

  • Migrating from on-premise to IaaS can be difficult.

  • Monthly costs can come out to be more than expected.


PaaS provides end users with a solution to only manage their hosted applications. Environment updates, OS patches, and everything is managed by the cloud providers.

It enables companies to manage things quickly because of its features like automation, availability, scalability, and cost-efficiency. Some examples of this service are Azure App Service, Azure Functions, and AWS Lambda.

Advantages of PaaS

  • It has no setup or maintenance costs for the software associated with it. Therefore, companies enjoy the low investment that PaaS offers.

  • It manages all the updates that are necessary to ensure that the system runs smoothly with the latest package installations, which is managed by the PaaS provider.

  • Its scalability feature makes it an ideal solution for companies. Its ability to scale up and down as per the CPU usage makes it different from the other services.

Disadvantages of PaaS

  • While PaaS providers manage the infrastructure and platform, companies are responsible for the security of the applications they build.

  • The users lack control over a PaaS service solution. They’re dependent on the providers for the same e.g., whenever the provider increases their pricing of services, the applications can become more expensive than the estimated budget.

  • When using PaaS, users sometimes have to deal with frequent downtimes. There can be power outages, disasters, or other misfortunes, all of which can lead to devastating consequences. This can impact both business operations and end users who use the application.


SaaS provides end users with applications that they can directly use and do their tasks on using a Wi-Fi or internet connection. It saves a lot of time that could be spent on managing software, updating OS patches, and other tasks. Some examples of SaaS are Office 365, Dropbox, and Shopify.

Advantages of SaaS

  • It offers numerous benefits for small businesses that don’t have the time, capital, or expertise to build their applications.

  • It is accessible 24/7 from any device having access to an internet connection.

  • It saves data periodically in the cloud. So, we don’t need to worry about data access.

  • It offers access to highly scalable reporting tools.

Disadvantages of SaaS

  • Users don’t have much control because the vendor manages everything, and we have to be dependent upon its capabilities.

  • Most SaaS applications offer limited customizations.

  • While the SaaS provider secures the application, strict measures need to be taken to deal with sensitive information.

Note: The SaaS market is filled with start-ups, and some of them don’t have enough experience to survive in a highly competitive market. In case a start-up fails, it’ll have to change its service provider, and it becomes cumbersome to transfer the company’s critical data from one service provider to another. Therefore, companies have to be prepared for such an event with a planned exit strategy.

Other cloud models

Nowadays, we often use the term environment as a service (EaaS) which means almost anything can be availed as a service. Here are some of the services:

  • Data analytics as a service
  • Hardware as a service
  • IT as a service

As models change, so do their roles and responsibilities. Now that we have covered some basics of the different cloud service models, let’s discuss the differences between on-premise software, IaaS, PaaS, and SaaS through a diagram in detail:

Two color components are used in the illustration above, blue and yellow, that represent the services provided by each model. For each model, the blue ones have to be managed by the organizations, and the yellow ones are managed by the cloud provider. The comparison between all these models is elaborated below.

  • On-premises: Organizations have to manage everything starting from the applications, data, runtime, OS, networking, and storage. So, if they opt for this type of architecture, they’ll have many responsibilities.

  • IaaS: The cloud provider takes on more responsibility as we move toward the other architectures from left to right. In the IaaS architecture, the cloud provider manages servers, storage, and networking and the organizations only have to manage their applications, OS, and runtime.

  • PaaS: The organizations’ responsibility is to manage their data and applications. Cloud providers will take care of all other things.

  • SaaS: Here, the cloud manages everything. The organizations’ responsibility is just to understand whether the software meets their needs or not. We can use it for our personal use as well e.g., Office 365.


  • As we move from left to right, toward SaaS, our systems become more insecure. So, we have to make sure that our organization’s policy allows us to do that. Directly jumping onto the cloud can be a potential security risk.
  • If our organization’s policy doesn’t include shifting entirely to the cloud, we can use the hybrid cloud architecture, where we can keep our data on-premises and deploy those applications over the cloud.

How to choose a cloud model

Let’s start with a scenario where we’re using an on-premises server and have to migrate to the cloud. We have two options, either we can choose a virtual machine or a web application.

Let’s understand the factors that will help us decide the service we need to choose:

Suppose we want to have full control of the OS and the infrastructure. We also want to manage everything on our own and don’t want to depend on the cloud provider for these services. In this case, we can rely on IaaS and opt for VM as an option.

On the other hand, if we only want to focus on application and data management, we should opt for PaaS and deploy our applications on Azure App Service.

If Azure App Service doesn’t support the application framework, we’ll use SaaS. We’ll have the same control as we would using a VM on the data center and we won’t have to change much of the configuration either.

Note: Logic Apps is a highly scalable integration solution that can help scale our business through automated solutions. We can do a bunch of things using Azure Logic Apps e.g., Twitter sentiment analysis, alerting the IT Staff if any incident takes place, and tracking customer feedback for scaling businesses.

Logic App
Logic App

Observe the illustration above and try to figure out the answer to the following question:

Quick Quiz


There’s a deployed demo Educative Logic App. Which category does it belong to (IaaS, PaaS, or SaaS)?

Show Answer