Software as a Service (SaaS) - Provides a complete software solution that you purchase on a pay-as-you-go basis from a cloud service provider.

Platform as a Service (PaaS) - Offers an environment for developing, testing, delivering, and managing software applications without the complexity of building and maintaining the infrastructure typically associated with developing and launching an app.

Infrastructure as a Service (IaaS) - Provides basic compute, network, and storage resources on demand, over the internet, and on a pay-as-you-go basis, requiring the user to manage the operating systems, middleware, and applications.

None of the above