Saas, IaaS and PaaS

We hear a lot about Software as a Service (SaaS) and its role in enabling applications to be provided in the cloud. Lately we have been hearing more about Platform as a Service and Infrastructure as a Service. IaaS essentially involves the provision of raw computer power and storage. PaaS, on the other hand, offers up not only the infrastructure but an operating system and an applications platform which customers can use to develop/configure their own applications. PaaS gives the customers more flexibility with the applications they use on the cloud than does SaaS, which is generally a bit restictive because the same apps need to be used by a variety of customers and the provider could not possibly support the apps if there were 100 variations on them being run.

IaaS and PaaS not only involve different customer experiences, they involve different strategies by the providers. So far, Amazon, as one of the major cloud providers, has stressed an IaaS service. Recently, on the other hand, Microsoft has been going into the PaaS route. The two rivals will therefore be attracting customers with different needs and desires, but also will be selling their wares on the basis of the differences they offer to the customers. The outcome will be instructive in gauging the future direction of cloud services. For an excellent article on the Microsoft initiative, check out this article.