Cloud Computing “Service Models”
Cloud computing is based on service models. These are categorized into three basic service models which are :-
Infrastructure-as–a-Service (IaaS)
Platform-as-a-Service (PaaS)
Software-as-a-Service (SaaS)
Anything-as-a-Service (XaaS) is yet another service model, which includes Network-as-a-Service, Business-as-a-Service, Identity-as-a-Service, Database-as-a-Service or Strategy-as-a-Service.
The Infrastructure-as-a-Service (IaaS) is the most basic level of service. Each of the service models inherit the security and management mechanism from the underlying model, as shown in the following diagram:
Cloud Computing Service Models
INFRASTRUCTURE-AS-A-SERVICE (IAAS)
IaaS provides access to fundamental resources such as physical machines, virtual machines, virtual storage, etc.
PLATFORM-AS-A-SERVICE (PAAS)
PaaS provides the runtime environment for applications, development and deployment tools, etc.
SOFTWARE-AS-A-SERVICE (SAAS)
SaaS model allows to use software applications as a service to end-users.
