Which cloud service model reduces the customer's management responsibilities the most?

Software as a Service (SaaS) offers the highest level of abstraction and reduces customer management responsibilities the most because the cloud provider manages all aspects of the application, including the underlying infrastructure, operating systems, and software. Customers simply use the application. Infrastructure as a Service (IaaS) requires the customer to manage operating systems, applications, and data, while the provider manages networking, storage, servers, and virtualization. Platform as a Service (PaaS) requires the customer to manage applications and data, while the provider manages operating systems, runtime, networking, storage, servers, and virtualization.