Discuss the three main service models of cloud computing.

What will be an ideal response?

? Software as a Service (SaaS): software and associated data are centrally hosted on the
cloud.
? Platform as a Service (PaaS): a computing platform that allows the creation of web
applications quickly and easily and without the complexity of buying and maintaining the software and infrastructure underneath it. Sometimes, PaaS is used to extend the
capabilities of applications developed as SaaS. While earlier application development
required hardware, an operating system, a database, middleware, Web servers, and other
software, with the PaaS model only the knowledge to integrate them is required. The rest
is taken care of by the PaaS provider.
? Infrastructure as a Service (IaaS): delivers servers, storage, network and operating
systems – typically a platform virtualization environment – to consumers as an on-
demand service, in a single bundle and billed according to usage. A popular use of IaaS is
in hosting websites, where the in-house infrastructure is not burdened with this task but
left free to manage the business.