Cloud computing represents a convergence of two major trends in
information technology — (a) IT efficiency, whereby the power of
modern computers is utilized more efficiently through highly scalable
hardware and software resources and (b) business agility, whereby IT
can be used as a competitive tool through rapid deployment, parallel
batch processing, use of compute-intensive business analytics and
mobile interactive applications that respond in real time to user
requirements [29]. The concept of IT efficiency also embraces the
ideas encapsulated in green computing, since not only are the
computing resources used more efficiently, but further, the computers
can be physically located in geographical areas that have access to
cheap electricity while their computing power can be accessed long
distances away over the Internet. However, as the term business
agility implies, cloud computing is not just about cheap computing —
it is also about businesses being able to use computational tools that
can be deployed and scaled rapidly, even as it reduces the need for
huge upfront investments that characterize enterprise IT setups
today.1