Certificate of Cloud Security Knowledge (CCSK) Practice Test 2025 - Free CCSK Practice Questions and Study Guide

The answer is correct because "Hardware as a Service" is not a recognized cloud service model within the traditional framework of cloud services. The well-established models include Infrastructure as a Service (IaaS), Platform as a Service (PaaS), and Software as a Service (SaaS).

IaaS provides virtualized computing resources over the internet, allowing users to rent infrastructure such as servers and storage. PaaS offers a platform that allows customers to develop, run, and manage applications without dealing directly with the infrastructure, simplifying the development process. SaaS delivers software applications over the internet on a subscription basis, enabling users to access software via a web browser without the need for installation on local devices.

In contrast, "Hardware as a Service" lacks a standardized definition and is not commonly included in discussions about cloud service models. While it may refer to a concept where hardware resources are provided on a subscription basis, it does not fit within the long-established classifications of cloud services, which focus on various layers of abstraction around infrastructure, platforms, and software.