Google’s cloud is a network made of perhaps a million cheap servers distributed in data centres across the World, storing numerous copies of the World Wide Web. This massive, distributed architecture makes searching extremely fast and provides a high degree of resilience, enabling individual servers to be replaced with faster machines after a few years with no impact on overall performance (Baker, 2007). Google and a few other companies with very large high speed distributed networks of computers, notably Microsoft and Amazon, realized that their computing resources were of value to other organisations and could be made available to them for a wide range of applications.
As with the term “VLE”, Cloud Computing has various definitions. Vaquero et al. (2009) examined more than twenty of them and proposed the following: