Cloud Computing Part 2: How is Cloud Computing different from SaaS?
Generally a Cloud offering, targets enterprises. There are many services being offered in the Cloud. Let us take the example of Amazon EC2 services. EC2 is a service across the internet, which provides computing power and the user pays only for the capacity used. The user is in complete control of what he/she wants to use the capacity for. There are numerous examples in the internet, showcasing instances on how a small business was able to quickly setup shop, on how another business was able to expand its capacity for the holiday season and quickly ramp down, paying for only what they used. In these instances, the application that runs and services the customer, is being developed and used only by that small business to cater to its customers. This cannot be called SaaS. SaaS is a pre built application having a pre defined set of features, targeting a specific end use. Companies using SaaS can take advantage of only these features with slight customization to meet their needs. What Amazon EC2 offers is Infrastructure as a Service (IaaS) or a Platform as a Service (PaaS). An enterprise using IaaS or PaaS can decide on what OS to use, what DB to use, what webhosting services to use and what application development environment to use. Of course, the choices are limited to the ones made available by the IaaS/PaaS provider.
So how are SaaS and Cloud Computing related? Cloud Computing is nothing but the bigger picture which includes SaaS, IaaS, PaaS, Web services, Utility Computing etc. While this is an attempt to clear the air on these terminologies, there is no consensus on whether they mean the same or how one is different from the other. There are many providers who claim to be offering Cloud services, while they may just be offering just utility computing or SaaS or any one of the variants possible under the bigger umbrella called Cloud Computing.
At the end of the day what matters is what the users want. The Cloud user typically wants to avoid infrastructure related headache and needs a reliable provider to provide him with that facility. If an individual user is interested in just photo sharing or just wants to watch his favorite video on in the internet, then there are providers who cater to such needs. If an online newspaper company wants to store all their articles, they just buy database space and make use of the pay as you use utility computing model. If an enterprise wants to implement a full fledged CRM system, they can choose from the number of SaaS providers. And if a corporate’s IT department doesn’t want to do anything with buying massive servers and maintaining huge data centers, they can just have their developers use the platform provided by the likes of Amazon (EC2), Google (App Engine), IBM (Blue Cloud), Microsoft (Azure) and Salesforce.com (Force.com) and reach out to their customers in the most efficient way. There can be multiple variations of these needs and services.
The four services mentioned above show the evolution of the Cloud paradigm. This revolutionary technology has made the enterprises take note of the potential to save big bucks especially in the infrastructure space.
This series of blogs on Cloud Computing will continue as the concept evolves. Feel free to post your thoughts on this as we together try to understand how this buzz takes shape in the future.

