Depending upon how an application is combined with elastic infrastructure, the function of the cloud service could change from Infrastructure as a Service to Softwareas a Service.
Beginning with the well-known Infrastructure-as-a-Service (IaaS), Platform-as-a-Service (PaaS) and Software-as-a-Service (SaaS) structure, Gartner added in a Business and Information Systems layer that includes brokerages, management and security.