Cloud Computing is a term which is rooted in the area of
computing architectures. It describes a concept which is closely linked to the grid-
computing technology, however in contrast to grid-
computing which is used in a more technical context,
cloud computing describes an architectural concept where computational services in form of applications, platforms, data and infrastructures are no longer situated on local systems but can be accessed on demand in a far-away
cloud of interconnected computers and servers. To access this remote system, which connects supplier and consumer, as well as entities of different
clouds run by different providers, defined interfaces or standard applications such as a web browser are used with the internet functioning as the access base (Hayes, 2008). In
cloud computing three possible forms of the
cloud can be distinguished, depending on what form of service is offered. The first one is Software as a Service (SaaS). As the name implies, SaaS-providers focus on offering software to their customers, who neither know about the underlying infrastructure, nor do they gain control over it. The second form is named Platform as a Service (PaaS), a further development of the SaaS-model, where PaaS-providers offer
computing platforms or portals. The idea behind PaaS is that developers don’t write their own home page etc. running on someone else’s servers. Instead, they programme web-based software applications, which they can then operate without having to buy, set up and maintain servers. These, on the one hand, streamline the access to software and, on the other hand, facilitate combinations of services, so called mash-ups. In addition, PaaS’ platforms and portals drastically affect software service sales through their network effects. As a counterpart to SaaS on the software side, the third form of the
cloud is Infrastructure as a Service (IaaS). IaaS-providers sell storage or processing capacities to their customers, which are placed at the disposal of the higher layers SaaS and PaaS. A well-known example of IaaS is Amazon’s Elastic Compute
Cloud (EC2), where customers can buy instances, paying on an hourly basis.
Learn more in:
Cultural Differences in Managing Cloud Computing Service Level Agreements