Cloud ComputingThere isn´t a universal definition of cloud computing, but various interpretations.

This might be explained by the novelty of the technology and its ongoing developments. The following three definitions should clarify the concept of cloud computing.

The definition of Accenture, a global acting management consulting, technology services and outsourcing company: "The dynamic providing of IT resources (hardware, software or services) through an external network" (Metzger, Christian; Reitz, Thorsten; Villar, Juan 2011, p 2)

A wider definition offers the International Data Corporation (IDC), a major market research and consulting company for information technology:

"IDC sees cloud computing as a technique and delivery model, with which cloud services are offered to companies and consumers via the Internet. The operation – for example the storage of data – is outsourced to a provider" (Metzger, Christian; Reitz, Thorsten; Villar, Juan 2011, p 2)

The National Institute of Standards and Technology (NIST), a US federal agency for technological standardization processes, published a very detailed definition:

„Cloud computing is a model for enabling convenient, On-Demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction. This cloud model promotes availability and is composed of five essential characteristics, three service models, and four deployment models." (Harding, Chris 2011, p. 2)

According to Metzger, NIST provides a dynamic and comprehensive definition of cloud computing that takes their individual components into account. (cf. Metzger, Christian;. Reitz, Thorsten; Villar, Juan 2011, p. 2)

In business models, cloud computing is also defined as a demand-oriented and flexible use of IT services, which are offered as service units via high-performance networks in real time and billed based on the usage.

As the definition indicates, the term cloud computing can be seen as a technology as well as a business model.