What is the difference of SaaS, PaaS and IaaS?

The fast development of storage, networking and processing capabilities brought a revolutionary way of how computing power is delivered to business. It was made possible thanks to large scale data centers connected to high speed and low-cost broadband networks.

Business now gets access to huge amount of data simply by plugging into the wall or connecting through Wi-Fi. More important, demands and expectations are constantly increasing as we start taking fast connection speed and secure access for granted, regardless of a geographical position. So it comes with no surprise, that the cloud solutions market is growing, gaining more user loyalty for the provided convenience. According to Gartner, the size of the cloud computing market has grown by 19% compared to 2016 and will reach the total revenue of $260 billion by the end of 2017.

Business no longer need to buy, build or manage costly facilities on site. Cloud has proven itself to be more reliable, affordable and secure. You only pay for features and tools you actually use, at the same time getting support and expertise from a solution provider. Understanding the difference between those confusing and widely mentioned acronyms is easy — all we need is to take a closer look at a cloud infrastructure and its components.

Cloud as a service

The cloud services make the whole process of data storage and management more efficient. The possibility to share resources and work with them from any location globally drive business results. The use of cloud vendor services allows any company to concentrate on business goals while outsourcing a part of the business process. The size of that part may vary significantly depending on corporate priorities.

Basically, there are three variations of how cloud services are delivered. Imagine a pyramid with IaaS being a base, PaaS — the middle layer, and SaaS — the top of the whole construction. So the three acronyms stay for three delivery models, with different scope of vendor responsibilities included in each of them.

Cloud as a service

IaaS or Infrastructure-as-a-Service

When deciding to use IaaS services, you want the cloud vendor to provide the stack up to virtualization level. The cloud vendor administer the infrastructure where you deploy your virtual machines, but still dealing with OS, middleware, runtimes, data and applications management. For example, let’s name Microsoft Azure here. Another ostensive IaaS service is Google Cloud Platform.

IaaS or Infrastructure-as-a-Service

PaaS or Platform-as-a-Service

In case you really want to focus on code and data, PaaS will be the right model, as you opt out from dealing with middleware installation, patch management or any updates.

PaaS is an environment with its programming languages, an operating system, a web server and a database. You can run your code while the provider takes care of the infrastructure up to the point shown on the picture above.

When using PaaS you only manage data and apps resources. This part of the mentioned above pyramid belongs to developers. The domain offers users fast and cost-effective development and easy deployment of web apps. Though there are certain issues connected with migration and developers can be limited by programming languages used.

Simply saying, when you are using PaaS, the cloud vendor does not only provide the virtualization layer for you, but also manages it. So you can concentrate on coding and deploying new applications in order to drive business and increase revenue.

Google App Engine is one of the well-known PaaS services.


SaaS is the icing on top of the cake. End customers simply enjoy working with an application, avoiding any possible headaches connected with software development and maintenance — especially when they think of a development process as something magical.

In case you just want to subscribe and start using the application right away for both personal and business goals, this cloud delivery variant is the most appropriate. You pay for access to the already developed software, get the account with the desired features and tools, while the vendor runs and manages the software on their servers.

No need for installation, maintenance or updating means lower costs for your business. With subscription being the only payment, you can access and manage your data from anywhere, anytime. Moreover, you minimize HR expenses associated with headhunting and personnel training.

We bet, you are an active SaaS user. Dropbox, JIRA, Office365, even LinkedIn are SaaS services that need no introduction.

Choosing the right model

The kind of model you choose depends on your business priorities. In fact, you may use a hybrid model that will include all three cloud computing models. The main thing about the described above Cloud-as-a-Service variations is that they give your company opportunities to switch resources from hardware and software maintenance, and employee costs towards alternative business needs.