The Differences Between SaaS, IaaS, and PaaS

By Lisa Gecko

There a several cloud computing models and each has their pros and cons. Add to these the numerous supporting technologies associated with each and it can be confusing to figure out the best option. In this series we will introduce these service models, and then take a deeper look at each.

The three primary types of cloud computing are SaaS, IaaS, and PaaS; software, infrastructure, and platform as a service. When you take a closer look, you’ll see that your company’s needs and comfort level will determine which service works best for you.

These services are made possible by virtualization, the availability of high-speed networks and the capabilities of today’s browsers. With these technologies in place, it becomes less necessary to own your own infrastructure, or even to own your own software. You can rent what you need from a cloud hosting service, as you need it.

The easiest way to understand these as-a-service offerings is to start with SaaS, the most virtual layer and the one you may already be using today on some level. Saas is simply a software service available over the Internet. The software has already been developed and you access it and make use of it through your browser.

SaaS provides benefits across your organization and is relatively simple to get started with. The host determines how many resources to utilize based on your needs. The host also provides the servers, the virtual machines, the network equipment, and technical support to maintain your cloud. In contrast to SaaS, IaaS is a more complex cloud host option, but no less easy to get started with. With an IaaS based cloud service, you can maintain control of your software environment, but you will not need to maintain any equipment. You won’t have to purchase servers and maintain them in a climate-controlled room or need expensive systems administrators. Instead, you rent the equipment from an IaaS provider.

With IaaS, you can run whatever software you want on your cloud. On the back end, the host provides storage or other resources as you need them. This is made easier with virtualization technologies, which isolate the physical hardware from the virtual machine you’re cloud is running on. IaaS is readily available from a number of providers, but care should be taken in choosing a host that is reliable and dependable with the latest software and hardware solutions.

PaaS is somewhere in between IaaS and SaaS. It’s not a complete software application like SaaS, and it’s not a complete cloud network, like IaaS. PaaS gives your application developers tools and resources to develop in-house software on a cloud based platform. The platform gives you tools to develop mobile apps, social apps, websites, office application and more. Your IT staff designs and develops its own custom software, but they use the APIs and tools to build and install them in the platform.