Which type of cloud service model gives users the least amount of control over underlying infrastructure?

Software as a Service (SaaS) offers users the least amount of control over the underlying infrastructure because it delivers software applications through the internet on a subscription basis. Users access SaaS applications via a web browser, and the service provider manages all aspects of the underlying architecture, including servers, storage, networking, and the software itself. This means users do not have direct control over the infrastructure or the application implementation; they simply use the provided services as-is.

In contrast, Infrastructure as a Service (IaaS) allows users to manage and configure virtualized computing resources directly, giving them more control over the infrastructure. Platform as a Service (PaaS) offers a middle ground, allowing users to manage applications and services while the provider maintains the underlying hardware and software environment. The Community Cloud model involves sharing infrastructure between several organizations, but in the case of SaaS, users have no control over how the infrastructure is configured or managed, emphasizing the level of abstraction and management taken on by the service provider.