SaaS, Paas and IaaS are the three types of services provided using “cloud”. Their common factor for providing services to organization and customer is the “CLOUD” depending upon the types of the service they need. SaaS provides Software service on cloud where PaaS provides Platform for application development and finally, IaaS provides Infrastructure.
The cloud is a very broad concept, and it covers just about every possible sort of online service, but when businesses refer to cloud procurement, there are usually three models of cloud service under consideration, Software as a Service (SaaS), Platform as a Service (PaaS), and Infrastructure as a Service (IaaS).