'Cloud Computing' is clearly the technology of the future in the computing world, on account of it's many advantages. However, it may come as a big surprise to many that it has nothing to do, whatever, with clouds, aircraft, spacecraft or devices positioned at high altitudes. Yes, satellites are used, to an amount, in computer communication, but that's about all that clouds have to do with cloud computing! There are not computers installed inside satellites that are orbiting the earth and so on (except the specialized ones that are part of the satellites themselves).
The origin of 'cloud', in the context of cloud computing, lies in Science / Math. According to Wikipedia, a cloud is '… a large agglomeration of objects that visibly appear from a distance as a cloud and describes any set of things which details are not inspected further in a given context'. In elementary graphs (or simple XY plots), clusters of points are called 'point clouds'. In Astronomy, a den agglomeration of gas and particulate matter in space is known as a nebula (Latin for mist or cloud). Similar is the meaning in Physics when we consider the indeterminate position of electrons around an atomic kernel (also known as a 'cloud') and so on. Applying this definition of 'cloud' to the realm of computing, a cluster (or network) of computers is a 'cloud of computers'. Thus, finally, the term 'Cloud Computing' which implies computation performed by networks of computers (in which members are located conveniently close to each other) all over the globe. (Of course, the clusters may also be inter-connected, leading to a global network of communicating computers.)
Physically, computers in the 'Cloud' are on earth itself. And, in those very places they are now exist! When we need to take an abstract view (as in the case of software design, planning and budgeting exercises), physical details are irrelevant and we find symbols extremely useful since they convey what was intended clearly, yet use very little space and hide unnecessary details .
Finally, why are all the IT bigwigs heading for the Cloud these days? The following four major benefits together form the answer to this question:
1. Much more efficient use of computers resulting in the need for far fewer computers in operation than now, to meet the world's computing requirements.
2. Energy savings from the use of fewer computers (a direct consequence of point 1 above).
3. Cost savings on account of both of the above.
4. Reduction / Slowdown in Global Warming (due to point 2 above)
Source by Abraham R Chacko