The National Institute of Standards and Technology (NIST), an arm of the US Department of Commerce, published a NIST Definition of Cloud Computing.
photo credit: Miran Rijavec
The NIST definition of cloud computing can be broken down into 3 facets: the essential characteristics, the service models and the deployment models.
Essential characteristics:
• On-demand service
• Broad network access
• Pooling of resource
• Elasticity
• Measured service
Service models
• Software as a service (SaaS)
• Platform as a service (PaaS)
• Infrastructure as a service (IaaS)
Deployment models
• Private cloud
• Community cloud
• Public cloud
• Hybrid cloud
The NIST definition does not include a pricing model for cloud computing services since this has nothing to do with the nature of the service. The pricing model may be subscription pricing, a perpetual license, or some other form of pricing.
