VNUNet - Managing Identities in the Cloud
For many years, the internet has been depicted in diagrams as a cloud, so it is hardly surprising that the term 'Cloud computing' has been taken up to describe a computing paradigm in which software and services are accessed over a network. In contrast to traditional software distribution models, where applications are licensed per user and installed on end-user devices, users access applications on the internet when needed. Cloud computing builds on earlier types of grid or on-demand computing, where applications and services are provided as a utility model, such as that used for electrical power. In such a model, users are charged for the actual usage of services.