When the United States National Institute of Standards and Technology (NIST) published the cloud computing definition, they also defined the essential characteristics of this new model. These have come to be more important than the definition in that the characteristics have helped to define and protect the marketplace against all the marketing hype that has accompanied the cloud.
The first characteristic of cloud computing is that it is an on-demand, typically self service model. On-demand, meaning that it can be purchased when needed, for as long as needed, and given back when finished. Self service refers to the consumer's ability to buy, deploy and shut down services without any assistance from the service provider. This speeds up the process controls cost and moves control to the consumer. (Refer back to earlier paragraphs...