1. Introduction : 1.3 Service Model
1.3 Service Model
The National Institute of Standards and Technology (NIST) specifies three service layers in a cloud. VMware defines these service layers as:
*Software as a Service (SaaS) – Business-focused services are presented directly to the consumer from a service catalog.
*Platform as a Service (PaaS) – Technology-focused services are presented for application development and deployment to application developers from a service catalog.
*Infrastructure as a Service (IaaS) – Infrastructure containers are presented to consumers to provide agility, automation, and delivery of components.
Figure 2. Service Models
The service model for the service definition in this document is primarily IaaS, for an organization to provide Infrastructure as a Service to consumers of vCloud services through a catalog of predefined infrastructure containers. The IaaS service layer serves as a foundation for additional service offerings, such as PaaS, SaaS, and Desktop as a Service (DaaS).