“ A model for enabling ubiquitous, 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.”
~~The National Institute of Standards and Technology
On-demand self-service - Service consumer can procure or enable computing resources such as storage as needed without requiring personnel contact with the service provider
Broad network access - These computing resources are available over the network and accessed through various form of standard devices
Resource pooling - Computing resources such as memory, processing, bandwidth, storage are pooled together by service providers to serve multiple consumers under the multi-tenant model, assigning and re-assigning such resources according to demand
Rapid elasticity - This is so that services can scale rapidly outward and rapidly released to scale inward on demand
Measured service - Cloud systems leverage a metering capability to automatically manage and optimize resource usage at level of abstraction suitable to that level of
service
Software as a Service (SaaS) - Service provisioning under this model is for users or consumers to use a provider’s application running on its infrastructure at a remote location on demand, in that, a single instance of the application is available to multiple end-users. In other cases, different instances of the same application are deployed for different consumer.
Platform as a Service (PaaS) - The service provision on this model is the deployment of applications acquired or developed by end-user onto the infrastructure of service provider using tools and programming languages supported by such.
Infrastructure as a Service (IaaS) - The provisioning of computing resources such as operating system, storage, servers, processing, bandwidth, datacenter space and sometimes applications are pooled together and made available by service providers to
handle tasks and processes.
Private Cloud - A cloud infrastructure built entirely for a single organization and its business units and managed either by its own human resource or third party organization.
Community Cloud - A cloud infrastructure set up for several organizations with common interest and concern. Like private cloud, it can be managed either by member of its staff or third party organization.
Public Cloud - The provisioning of cloud services is rendered by an organization to the public.
Hybrid Cloud - The provisioning of two or more cloud deployment models networked by standards or proprietary protocols that allow portability of traffic such as cloud bursting activity between clouds