Which of the following cloud computing service models is NOT defined by NIST?

The cloud computing service models defined by the National Institute of Standards and Technology (NIST) include Software as a Service (SaaS), Platform as a Service (PaaS), and Infrastructure as a Service (IaaS). Each of these categories has specific characteristics that are recognized and standardized by NIST, which helps to create a clear framework within the cloud computing domain.

Desktop as a Service (DaaS), while a recognized model in certain contexts and often discussed in the industry, does not have the same formalized definition by NIST as the other three service models. DaaS typically refers to a cloud computing service where the desktop environment is hosted in the cloud and accessed remotely, but it falls outside the core definitions that NIST outlines for cloud computing service models.

Understanding NIST's role in defining these service models is essential, as it influences how organizations and professionals communicate about cloud services and their capabilities. The formal definitions help ensure a common understanding and provide guidance for businesses when adopting cloud technologies.