Cloud Computing- Difference between SaaS, PaaS and IaaS


Cloud Computing Gontu Series

Cloud Computing is a big BUZZ! in every nook and corner of IT Industry. Now, every Organization small or big striving to get their offerings on CLOUD. But, what it  means– offerings on CLOUD ? CLOUD based solutions ? These questions may haunt any newbie who does not know much or anything about Cloud computing.

In this post I would give you an overview on CLOUD and will get you through the various offerings which can be bundled in a CLOUD solution.

Cloud ComputingCloud Computing refers to accessing applications, data or services that are stored or running on remote servers over internet. The CLOUD in “Cloud Computing” refers to Internet (a network). So, in simple terms, you may define “Cloud Computing” as computing over internet. The companies which offer CLOUD based solutions in actual gives some kind of services over a network.  The services can be:  suppose you are running a company; and for some reason you need to buy costly servers (Hardware) for you business.  Now, you can do two things:

1. You go and directly buy the hardware.

2. You do not buy the hardware but you use someone else’ hardware and pay them money based on your needs concerning  the usage of hardware and the time frame for which you are going to use it. Hardware would not reside in you company physically but, over internet (on some network) you would be using this hardware for running your applications, storing data etc.

If you go with the second option; this means that you are utilizing services offered by someone on the network. In this case, these services means providing hardware on subscription bases. The organizations who are offering such services are known as CLOUD service providers. But, Cloud computing is not really limited to providing hardware related services; it can be any service: you may utilize someone else’ Software and pay subscription fee for that or may be for developing your own web application you would utilize tools which are offered as a service on Internet by someone else.

As a Cloud solution offering, an organization can broadly deliver three kind of services: 

SaaS (Software as a Service): 

…software that is deployed over the internet… With SaaS, a provider licenses an application to customers either as a service on demand, through a
subscription, in a “pay-as-you-go” model, or (increasingly) at no charge when there is opportunity to generate revenue from streams other than the user, such as from advertisement or user list sales.

PaaS (Platform as a Service): 

Platform as a Service (PaaS) brings the benefits that SaaS bought for applications, but over to the software development world. PaaS can be defined as 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. PaaS is analogous to SaaS except that, rather than being software delivered over the web, it is a platform for the creation of software, delivered over the web.

IaaS (Infrastructure as a Service): 

Infrastructure as a Service (IaaS) is a way of delivering Cloud Computing infrastructure – servers, storage, network and operating systems – as an ondemand service. Rather than purchasing servers, software, datacenter space or network equipment, clients instead buy those resources as a fully outsourced service on demand.

In the subsequent posts, I would be writing a case study suggesting how Organizations are cutting down huge costs significantly around the world using the concept of Cloud Computing.