Much is being written and spoken about cloud computing, by IT analysts, industry and business leaders and others. Some believe it is a disruptive trend representing the next stage in the rvolution of the Internet. Others believe it is hype, as it uses long established computing technologies. So, what is cloud computing? From a user perspective, cloud computing provides a means of acquiring computing services without requiring understanding of the underlying technology. From an organizational perspective, cloud computing delivers services for consumer and business needs in a simplified way, providing unbounded scale and differentiated quality of service to foster rapid innovation and decision making. It is a service acquisition and delivery model for IT resources and, if properly used within an overall IT strategy, can help improve business performance and control the costs of delivering IT resources to the organization.