In which cloud service model is the customer responsible for maintaining the operating system?

In the Infrastructure as a Service (IaaS) cloud service model, the customer has the responsibility for maintaining the operating system. IaaS provides the fundamental building blocks of computing, including virtual machines, storage, and networks. In this model, customers have control over the operating system and can install and manage their software, including middleware and applications.

This level of control means that the customer is tasked with updates, security patches, and any configurations needed to keep the operating system running smoothly. In contrast, in Software as a Service (SaaS), the cloud provider manages everything, including the operating system, while Platform as a Service (PaaS) offers a platform allowing users to develop applications without concern for the underlying infrastructure or operating system. Container as a Service (CaaS) lets users manage containerized applications, with the operating system typically being managed by the provider, making those options clearly distinct from IaaS.