Well it’s going to be big (and is already being hyped as such). It’ll be a paradigm shift in the world of IT as we know it. But as I explained in an earlier post: we still have a long way to go before it’ll be mainstream. Cloud Computing is the come together of multiple technologies that already exist. It can be compared to a chemical reaction : Every component is there, we are now in the process to evolve to a new level in IT.

Defining Cloud Computing seems to be something that nobody can agree upon. Here goes mine:

Cloud Computing is an IT model which allows business to scale IT capabilities in such a way that it suits the needs at any time. This can be realized real-time through on-demand self-service. It will be delivered as-a-service anytime, anywhere and will be paid per use afterwards. 

Such a definition can be broken down into 4 characteristics that build up Cloud Computing:

• Elastic & dynamic infrastructure; The infrastructure on which Cloud Computing is build should be able to handle the ever changing demand from business. In such in needs to be elastic and dynamic to supply this demand. Virtualization is the method to provide this flexibility.
• On-demand self service; Business needs to have the ability to self service their needs real-time. Controls should be provided that service this need without the help of external parties.
• Location independent; End-users should be able to access the service anytime, anywhere. Internet is the highway that will connect the service to standard input devices.
• Pay per use; A consumption model must be in place where one pays for the services that have been provided to them. No more, no less. Just the capacity that has be used should be billed afterwards. 

For more information look at the following information sources :

NIST Working Definition Of Cloud Computing

Maria Spinola – An Essential Guide to Possibilities and Risks of Cloud Computing (whitepaper)

Burton Group – Cloud Computing: Transforming IT (whitepaper / needs free registration)