Cloud computing is meant to provide better utilization of computing resources, scalability,backups and reliability through the use of multiple sites proving services. This efficiency establishes cloud computing as a type of green computing. As the studies done by NIST indicate, the Federal Government is interested in the benefits of cloud computing. Individuals and small businesses, especially startups, find cloud computing a way to concentrate their resources on establishing the business, rather than diverting money to infrastructure.

The NIST Cloud Computing Program was formally launched in November 2010 and was created to support the federal government effort to incorporate cloud computing as a replacement for, or enhancement to, traditional information system and application models where appropriate.The National Institute of Standards and Technology (NIST) has been designated by the Federal Chief Information Officer (CIO) to accelerate the federal government’s secure adoption of cloud computing by leading efforts to identify existing standards and guidelines. Where standards are needed, NIST works closely with U.S. industry, standards developers, other government agencies, and leaders in the global standards community to develop standards that will support secure cloud computing

Cloud Consumer: a person or organisation that maintains a business relationship with, and uses service from, Cloud Providers. Cloud Provider: A person, organisation, or entity responsible for making a service available to interested parties. Cloud Auditor: A party that can conduct independent assessment of cloud services, information system operations, performance and security of the Cloud implementation. A Cloud auditor can evaluate the services provided by a Cloud provider in terms of security controls, privacy impact, performance, etc. Cloud Broker: An entity that manages the use, performance and delivery of cloud services, and negotiates relationships between Cloud Providers and Cloud Consumers. Cloud Carrier: An intermediary that provides connectivity and transport of cloud services from Cloud Providers to Cloud Consumers.

The IBM Cloud Computing Reference Architecture (CC RA, see figure 2) defines the fundamental architectural elements constituting a cloud computing environment. The CC RA is structured in a modular fashion in a sense that on its highest level of abstraction, the main roles and the corresponding architectural elements are defined allowing to drill down for each of these elements as needed.

The IBM Cloud Computing Reference Architecture defines three main roles: Cloud Service Consumer, Cloud Service Provider and Cloud Service Creator. Each role can be fulfilled by a single person or can be fulfilled by a group of people or an organization. The roles defined here intend to capture the common set of roles typically encountered in any cloud computing environment.

A cloud service consumer : is an organization, a human being or an IT system that consumes (i.e., requests, uses and manages, e.g. changes quotas for, users changes CPU capacity assigned to a VM, increases maximum number of seats for a web conferencing cloud service) service instances delivered by a particular cloud service. Cloud Service Creator: The Cloud Service Creator is responsible for creating a cloud service, which can be run by a Cloud Service Provider and by that exposed to Cloud Service Consumers. Cloud Service Provider: The Cloud Service Provider has the responsibility of providing cloud services to Cloud Service Consumers.