SaaS vs IaaS vs PaaS Simple Definition & Best Features

Cloud computing has been a heated topic in today’s technology industry. Actually, cloud computing is not a new concept. It was invented in the early 1960s and it came into use in the modern context about 15 years ago when Google first introduced the term to the industry.

However, there has been a rapid shift towards cloud computing in business operations in recent years. Although in the past, only large companies could deploy cloud computing solutions due to high investment cost, the current expansion of cloud service models including SaaS (Software-as-a-Service), PaaS (Platform-as-a-Service), and IaaS (Infrastructure-as-a-Service) has allowed businesses of any size to access the clouds. Shifting to the cloud is a big decision and a deep understanding of the different features of these three cloud services is always highly recommended. 

What kinds of computing services can these models offer to your business? Interestingly, the answers lie in their names. SaaS (Software-as-a-Service) provides access to third-party software on the Internet. In terms of PaaS (Platform-as-a-Service), cloud providers handle the platforms where you build your business data and applications. IaaS (Infrastructure-as-a-Service) brings you computing and storage infrastructure, assisting you to create your platform. Nevertheless, there are many more important things you need to know about these models than just their names.

SaaS vs PaaS vs IaaS

What is SaaS?

SaaS (Software-as-a-Service): Out of the three models, SaaS applications can be the most familiar to you. To understand more about this model, now let’s take a look at Gmail. Are you aware that it is a software service that can store all your data and allow you to get access to it anytime you want and from any devices that you are using (web browsers, cell phones, etc.) as long as there is an Internet connection?. Generally speaking, SaaS delivers a software application that can be used and purchased on-demand via the Internet. As the software runs on the cloud, it does not require any specific installation on your devices. Now let’s think a bit more. If many people can use the service on the same cloud, how can the data of different user experience be segregated? Actually, for each subscribing cloud user, there is also a corresponding instance of the SaaS application running on the cloud. Therefore, SaaS can perform what is known as application customization, letting customers alter the configuration and store their data. 

Example: The embracement of SaaS products can range from personal use to business deployment. Some popular SaaS products that can be listed are Netflix, Facebook, Google Workspace apps, Microsoft 365, Shoeboxed, Zoom, Adobe Creative Cloud, Amazon Web Services, Slack, etc. 

What is PaaS?

PaaS (Platform-as-a-service): Instead of providing you specific and finalized on-the-cloud apps that you can directly consume as SaaS, PaaS offers a cloud deployment platform so that you can freely write and develop your own applications, regardless of whether they are completed or still in progress. A PaaS is a great tool for your company’s in-house developers to create more customized applications for your customers. These PaaS platforms present you with a high level of abstraction. In addition to creating software by using the tools and libraries from the cloud providers, you can set up the configuration and get control over the software deployment. Your developers do not have to be concerned with the needed quantity of memory or processors your application will consume as the cloud vendors will handle all data center resources assisting the tools. All your company needs to manage is the data and applications. This can save your company a lot of time and money because you do not need to purchase and manage the underlying hardware and software. There are many different types of PaaS platforms, but they all provide you with app hosting, deployment environment, and other related services. 

Example: Window Azure, Rollbase, Google App Engine, Long Jump, etc. 

What is IaaS?

IaaS (Infrastructure-as-a-service): In the IaaS model, you are provided with a virtual server for a while and charged based on the amount of resources you have used. You are allowed with the accessibility of infrastructure via the Internet that includes server, storage, other peripherals devices as well as managed services assistant operations and applications instead of buying infrastructure outright. If you need storage or virtual machines to develop your own platform, you can count on the IaaS model. Moreover, as you can use a Web-based interface regarded as a console to manage your IT operations, you are able to self-provision this infrastructure. In simpler words, you can scale the infrastructure up or down depending on your need after installing the needed operating systems and applications. 

Example: One famous example is Amazon EC2, providing its customers even with virtual resources that can be listed as CPU, memory, OS, and storage. Others are Flex Metal Cloud, Cloud Infrastructure by Google, Cloud Services by IBM, Digital Ocean, Linode, Cloud Services by Alibaba, Hitachi Enterprise Cloud, Hewlett Packard Enterprise, Open Cloud by Rackspace. 

The Differences Between SaaS, PaaS, and IaaS

1. Different users

SaaS model: Business sectors or individuals who are seeking to complete a business task without owning any IT equipment. For example, startups and small businesses tend to use SaaS apps because of the lack of time, capital, or expertise, or large companies seek short-term software. 

PaaS model: Companies that have efficient developers and deployers. They usually want to create customized applications and services to meet the needs of their customers. 

IaaS model: Most IaaS model users are system managers who want to create a platform for their service test, development, integration, and deployment.

2. Different cloud services

The cloud vendors will handle all of the tasks in the SaaS models, fewer in the PaaS models, but the least in IaaS models. To understand more about the relationships of the services offered by SaaS, PaaS, IaaS are offering to you, you can take a quick look at the diagram below: 


Just imagine this. You want a new house. There are usually three options for you. The first option is the least time-consuming. You just buy a completely built house. You do not have to do anything. Everything you need to do is to pay, move into the house and start your life there. However, as the house was built by others, sometimes you may not be satisfied with some features of the house. It is just like the way you use SaaS applications. Some of the currently available SaaS services are Email, Office, Automation, CSR, website testing, Wiki, Blog, Virtual Desktop, etc. You do not need to manage anything when using these services. The cloud vendors will take care of the system management from A to Z. You just purchase the applications and get your tasks done. However, you may find some of the applications’ features not yet match what you desire due to the different needs of your business.


The second option for you is that you have to design the house by yourselves, but someone else will gather all the needed materials, build the foundation of the house and build the rest for you. This time, you get a little more control over how your dream house will look like. However, you do not need to worry about how many bricks you are going to need. This is like when you use the PaaS model which can offer you greater flexibility and facilitation in operations. You are assisted with Service and application test, development, integration, and deployment, platforms on which you can build your own apps. You need to manage the data and the apps only.


The third option is the toughest one for you. You have to start from scratch. Luckily, some people can get you all the bricks, cement, all other materials you need, and they are kind enough to help you finish the foundation of the house. But then, you have to take care of the rest. You have to design the house, build walls, build the whole house by yourself. The building materials, as well as the foundation here, represent what IaaS offers to you: Virtual machine, operating system, Message queue, Network, Storage, CPU, memory, and backup services. IaaS can give you the infrastructure of cloud-based technology, direct control over the IT operations so that you can start building your own platforms and everything else.

Advantages and Disadvantages of SaaS vs IaaS vs PaaS

Advantages of the SaaS: 

  1. Time-saving: As mentioned before, you just need a device and Internet connection to get access to the SaaS. Moreover, as the cloud vendors take charge of the management and maintenance process, SaaS services can save you from many working hours.
  2. Cost-efficient: A lot of costs including hardware, software license, and maintenance can be cut down due to multi-tenant cloud environments.
  3. Scalability: the pay-as-you-go model can facilitate the user experience and offer you flexibility. As the third party hosts the software, switching usage plans is hassle-free. 
  4. Customer-friendly: Saas applications are easy to use and equipped with the best practices. Moreover, you can test the software before purchasing. 

Disadvantages of SaaS:

  1. Data insecurity: Embracing the SaaS model also means that you let the third party keep your data, exposing your business to security risks. 
  2. Difficulty in Regulation Compromise: As your data resides in the vendor’s data center, it may be difficult for you to agree with the vendor in terms of protection terms and conditions as both parties have different interests. 
  3. Low Speed: As the software runs on the cloud, a distant data center, you may have to endure lower performance. 
  4. Lack of customization: SaaS apps have been completed in advance of the purchase, which makes cloud vendors hesitate to make adjustments as you request. 

Advantages of PaaS: 

  1. Cost and Time savings: cloud-based services save up costs and times from hardware/ software or maintenance. 
  2. More control over schedules: As your developers will create new apps for your business, you can adjust the speed of the app development process. 
  3. Customization: It is easier for you to make changes to apps to meet the demands of your customers. 
  4. Continuous updates: you can get automated updates and security patches from your vendors, minimizing incompatibility. 

Disadvantages of PaaS: 

  1. Data insecurity: Even though you can run your own apps, the data is stored in the third party’s cloud servers. There is still a level of data risks. 
  2. Requirement of coding expertise: your developers must be competent at coding to make the best out of PaaS. 
  3. Limitation in the operations: Some customization processes may not perform best on PaaS platforms, causing inconvenience to end-users.

Advantages of IaaS: 

  1. Operational Flexibility: IaaS is the most flexible cloud service model, allowing your employees to get access to hardware, computing power, and software applications used on a daily basis. 
  2. More Control: you can retain complete control of your infrastructure 
  3. Scalability: Speaking of industries suffering from seasonal fluctuations, IaaS is an ideal choice to adjust the data storage, virtual machine, or software app needs. 
  4. Cost savings: IaaS offers lower infrastructure costs, making IaaS appropriate for startups.

Disadvantages of IaaS: 

  1. Higher requirement of internal resources and HR training: As your company needs to be responsible for multiple tasks, the workforce must acquire skills to manage the infrastructure. Inhouse resources are also needed to maintain stable control over the infrastructure. 
  2. Data Security: Threats can still be imposed by the host or other virtual machines (VMs), or even the data communication exposure between the host and VMs. 
  3. Complicated legacy systems: incompatible infrastructure may fail to secure legacy apps.


If you are considering scaling up your business, moving your business to the cloud is of paramount importance to ensure facilitation in operations as well as improvement in data security. Especially when your company has unpredictable demands, bounded resources, or a small size team, cloud computing provides solutions to all your addressed concerns. The real question you need to ask yourself is not whether to perform cloud migration, but which types of cloud service models among SaaS, IaaS, and PaaS you should embrace into your business.