Delivery Models of Cloud Computing

Based on the delivery models Cloud can be classified into four major categories:

1) IaaS (Infrastructure as a Service)
2) PaaS (Platform as a Service)
3) SaaS (Software as a Service)
4) BPaaS(Business Process as a Service)

IaaS (Infrastructure as a Service): On the subscription basis, the cloud provides the infrastructure services to the users.The services are like storage and backup infrastructure, designed VMs etc.Mainly deals with hardware type of resources.Best examples are Rackspace, Amazon EC2.

PaaS (Platform as a Service) :On the subscription basis, the cloud provides the platform services to the users.The services are like middleware, web server stack etc.Best examples are tomcat servlet container as a service,Microsoft Azure.

SaaS (Software as a Service) :On the subscription basis, the cloud provides the software services to the users.The services are like ERP,CRM etc.Mainly deals with software type of resources.Best example is Google Apps. The main advantage is that the users don't have to maintain any license.

 BPaaS(Business Process as a Service) :In this the cloud provides the business processes services to the users along with the staff that is required to run the business processes. The main advantage is that the users don't have to maintain any license or hire any staff to use the business process services.

Cloud Computing

Virtualization