Which cloud service model allows the least amount of control for customers?

The Software as a Service (SaaS) model allows the least amount of control for customers because it provides fully managed applications that run on the provider's infrastructure. In this model, end users have access to software applications over the internet but do not manage the underlying infrastructure, platform, or middleware.

With SaaS, everything from the application to the data storage, networking, and even the hardware is largely handled by the service provider, leaving users to focus solely on using the software itself for their needs. This encapsulation of management is advantageous for users who prefer an out-of-the-box solution without the need to configure or maintain the system themselves.

In contrast, Infrastructure as a Service (IaaS) offers customers extensive control over the infrastructure, including virtual machines, storage, and networks. Platform as a Service (PaaS) provides a platform allowing customers to develop, run, and manage applications without dealing with the complexity of building and maintaining the underlying infrastructure, but still allows for customization and application control. Data as a Service (DaaS) similarly gives users some level of control, particularly over data access, but still requires some management of data and services. Therefore, among these models, SaaS is indeed the one that provides users