What is “Cloud” Computing?…..
There is a lot of confusion around “Cloud” computing. This is mainly caused by every vendor bringing out a “Cloud” product or service.. Even wikipedia descriptions is a little too confusing for my liking.. http://en.wikipedia.org/wiki/Cloud_computing.
Cloud Computing breaks down into three main “Service Offerings” or “Service Pillars”. Which are Infrastructure, Platform and Application.
The following “as a Service” terms are used to describe these Service Pillars, which also describes the advantages of “Cloud” computing.
- Infrastructure as a Service (IaaS) [Compute and Storage]
- Platform as a Service (PaaS)
- Software as a Service (SaaS)
So, the key terms to describe “Cloud” Computing is:
- as a Service – This describes converting traditional IT to Self Service, Pay-per-use models and allot more benefits.. You can read more about the benfits of Cloud Computing in my articles filed under “Cloud” – http://virtualizationandstorage.wordpress.com/category/cloud/
- Service Pillars – This relates to, what part of the OSI model is managed by the cloud provider and what part is consumed by the customer..
- Public Cloud – Service Pillar or Service Offering built for public use
- Private Cloud – Service Pillar or Service Offering built for internal Enterprise use
- Hybrid Cloud – combination of both Public and Private (Actually, this description is incorrect.. Hybrid Cloud is a Internal IT network connected via a L2 Bridge into a Cloud Services.. Providing a secure connection into a Cloud services over the internet or a dedicated network. Examples: Amazon AWS Direct Connectaws amazon.com/directconnect; NetScaler CloudBridge
- “Personal Cloud” – this really isn’t a Service Pillar, its just away to describe that people will need access to their own personal applications and data within each of the service pillars. For me this is a Single Sign on Solution to connect everything seamlessly and access to personal data locally via cloud.
This IDC report explains in detail Cloud Best Practice.. :- Cloud Best Practices for Selection
Imitation Is The Best Form Of Flattery OBT 3 (I prefer Reference to my Blog !!!)
Cloud Computing – http://csrc.nist.gov/publications/nistpubs/800-145/SP800-145.pdf
Definition of cloud computing from the National Institute of Standards and Technology (NIST), IT services that are delivered as cloud services offer:
- A pay-as-you-go model with minimal or no initial costs
- Usage-based pricing, so that costs are based on actual usage
- Elasticity, so that users can dynamically consume more or less resources
- Location independence, high availability, and fault tolerance
- Ubiquitous access to services, where users can access services from any location using any form factor
The Economics of the AWS Cloud vs. Owned IT Infrastructure is a great article discussion the benefits of Cloud
My older post on the same – http://virtualizationandstorage.wordpress.com/2010/06/24/what-is-cloud-my-2-cents/



I think you have done an exceptional work by posting such a magnificent article. We can say that cloud computing is a general term for anything that involves delivering hosted services over the Internet. I personally believe this information about cloud computing would surely help most of the people who will read this.