SOLVED: In Simple Terms What is IaaS, PaaS and SaaS (as a service)?

what-is-iaas-paas-saas-as-a-serviceIn today’s cloud oriented world, it is easy to get confused with the “as a service” acronyms.  They are quite simple to understand if you ignore the sales jargon:

  1. What is Anything “As As Service”?

    aaS means that you are renting something rather than buying something.  If you connect to it online (and it is not hosted inside your company) it is an ‘as a service’ product.

  2. What is “Infrastructure as a Service”?

    IaaS means virtual machines you own and operate but that run on internet hosted hardware.  IaaS, means you need to install, configure, patch, secure… your VM’s but you rely on an internet company to buy and maintain the hardware (+electricity +cooling + physical security +…).

  3. What is “Platform as a Service”?

    PaaS means back-end applications that run on an internet hosted hardware.  PaaS allows you to use SQL database or a File Server with your data hosted on someone else’s server and operating system.  In this case you are not responsible for installing or patching the application (like SQL), but you are responsible for the data in that database and how that database is accessed (security, data input GUI, reports…)

  4. What is “Software as a Service”?

    SaaS means web based application.  SaaS means you are responsible only for the data.  The cloud company providing the SaaS, is responsible for the hardware, software, patching, enhancements… . Think of Google Maps, MS Office Online or Quick Books Online.

These As A Service solutions are used mostly to reduce cost and increase scalability.  The idea is that if your company needs ‘more’, it gets more on demand rather than having to wait for the procurement, deliver, installation, and configuration processes.  This also means that in most cases, if your company needs ‘less’, it can start paying for ‘less’ with just a few clicks.


There are thousands of webpages that explain these terms but if you are still confused, THIS Microsoft Technet blog post will provide some clarity.

Questions or Comments?