Which service model provides virtual machines and hardware through a service API?

Infrastructure-as-a-Service (IaaS) is the correct answer because this model offers virtualized computing resources over the internet. In IaaS, users can access essential computing infrastructure such as virtual machines, storage, and networks through a service API. This allows users to dynamically allocate and configure these resources as needed, granting them the flexibility to scale up or down based on demand without the burdens of owning and maintaining physical hardware.

IaaS is best suited for businesses and developers who require significant control over their computing resources and the ability to manage workloads efficiently. This model provides a foundation for deploying applications and managing data without the complexities of hardware management.

The other service models differ in their functionality and offerings. Software-as-a-Service (SaaS) focuses on delivering software applications over the internet, entirely managed by a provider. Platform-as-a-Service (PaaS) provides a development environment with the necessary tools for developers to build, test, and deploy applications without managing the underlying infrastructure. Network-as-a-Service (NaaS) specifically addresses networking resources and services, offering virtual network infrastructures rather than virtual machines and hardware. Each of these models serves different needs within the cloud computing landscape.