Which cloud service model supplies the consumer the ability to use applications provided by the cloud provider over the Internet?

The software as a service (SaaS) model enables consumers to access applications provided by cloud providers via the Internet. SaaS operates as a subscription service, where software is licensed on a subscription basis. Platform as a service (PaaS) provides the necessary framework and underlying tools to build applications and services. Infrastructure as a service (IaaS) offers components for an entire network and system infrastructure. Hybrid models leverage both cloud and locally hosted systems.