Which cloud service model provides virtualized hardware such as virtual machines?

Which cloud service model provides virtualized hardware such as virtual machines?

• A. SaaS
• B. PaaS
• C. CaaS
• D. IaaS

Answer: (D)

Providing virtualized hardware like virtual machines is the essence of Infrastructure as a Service (IaaS). In this model you lease computing resources—servers (as virtual machines), storage, and networking—over the internet. You have control over the guest operating system and applications, while the provider takes care of the physical hardware and the virtualization layer. This setup lets you scale resources up or down on demand without buying or maintaining physical servers.

Software as a Service (SaaS) delivers complete applications over the internet, so you don’t manage or install the software or its infrastructure. Platform as a Service (PaaS) gives you a development platform with runtime and tools to build and run apps, but you don’t handle the underlying hardware or OS. Containers as a Service (CaaS) focuses on deploying and managing containers and their orchestration, rather than providing direct access to virtual machines as the primary resource.