The following five characteristics of cloud computing are created by the Gartner Group, according to Plummer, et al. (2009) and Mell and Grance (2009), and have a summariz-ing purpose for applying cloud computing in general (cited in Mora, 2009).
Service based – The technology is service-oriented, thus abstracting the con-cerns of the consumer with the concerns of the providers (Mora, 2009). The ser-vices are provisioned automatically without human interaction (Mell & Grance, 2009).
Rapid elasticity and scalability – The services are scaled upon demand by add-ing or removing resources depending on the demand (Mora, 2009). To the con-sumer these services may appear unlimited as they are purchased and left on the go (Mell & Grance, 2009).
Shared resources – Services share a pool of resources in order to build econo-mies of scale. Economies of scale are such that through increasing the output, costs of the services are decreased (Mora, 2009).
Pay per use – These services are tracked with usage metrics, enabling a “pay-as-you-go model”. (Mora, 2009) The tracking is done automatically as there are embedded mechanisms for doing that (Mell & Grance, 2009).
Ubiquitous network access – Services are delivered through the web, using web identifiers, protocols and formats and have an identical access (Mora, 2009). Those resources are available over the internet and can be accessed from any platform such as thin or thick clients, which includes PCs, mobile phones and so on (Mell & Grance, 2009).
2.1.6 Related Technologies and Definitions
Cloud computing is related to the field of distributed systems, as shown below, and is also dependent on technologies such as virtualization and load balancing in order to op-erate. There are some issues that arise from the field of distributed systems and distrib-uted computing, which is inherently connected to cloud gaming as it can be seen as a distributed system.
2.1.6.1 Distributed