Date Posted : 2 years ago

On a technological level, cloud computing is not new, but on a business level it is described as a "revolution" (BITKOM, 2009). The revolution and influence of cloud computing is therefore not in the technology itself, but in its use. This will create a new generation of products and services. To illustrate this revolution, a comparison can be made with the replacement of electrical generators by power grids in the early 20th century (Kirwan, 2008). At that time, in-house electricity generators were replaced by obtaining cheap, flexible and demand-oriented electricity from the wall socket.

Cloud computing is an amalgamation of long-existing technologies (Foster, et al., 2008). Since the beginning of the 1990s, the Internet has also been accessible to the general public via the World Wide Web (WWW). This laid the foundation for new business ideas. Web hosting developed in the mid-1990s, in which providers make their resources available as services over the Internet (Almeida, et al., 1998). This includes the provision of Internet storage, web servers, databases or e-mail accounts. In the further development of these services, applications were also made available via the Internet, as so-called "Application Service Providing" (ASP). Since 2005, grid computing has enabled distributed computing on loosely coupled computers (BITKOM, 2009). In this way, computing power and storage capacities can be called up from remote resources as required in order to work together on a problem at the same time (Velte, et al., 2010). With the help of virtualisation, such combined resources are represented as an abstract resource pool, which is at the same time the direct prerequisite for the implementation of cloud computing.

Cloud computing is made possible by huge server parks (networked computers) of companies such as Amazon, Microsoft, Google or IBM. Their systems provide far more power than they can consume themselves. According to a study, the average utilization of a server is only 10-15% (VMWare, 2009). This results in idle time, which

costs without generating benefits. The development of cloud computing described above is a major step towards the efficient use of hardware and software resources (cf. Figure 3) and thus counteracts the current money-wasting and environmentally damaging underutilization.

Figure 3: Technological Evolution of Cloud Computing

The ideal model of the "open cloud" is still in the start-up phase, as this requires the full cooperation of the various cloud providers (, 2011). In order to ensure this interoperability, the creation of and compliance with common standards is a fundamental challenge that has yet to be overcome.