Cloud computing services are commonly classified into how many primary service models?

Cloud computing services are commonly classified into how many primary service models?

• A. Five
• B. Two
• C. Four
• D. Three

Answer: (D)

Cloud services are commonly described in three primary service models, each offering a different level of control and responsibility. Infrastructure as a Service provides the basic building blocks—virtual machines, storage, and networking—so you manage the operating system and applications while the provider handles the hardware and virtualization layer. Platform as a Service sits on top of that, giving you a managed development and runtime environment; you focus on writing code and deploying apps, while the platform handles the operating system, middleware, and runtime. Software as a Service delivers fully ready-to-use applications accessed over the web, with maintenance, updates, and security handled by the provider. These three capture the standard spectrum from raw infrastructure to complete software solutions, which is why they’re taught as the primary classifications. The other counts don’t reflect the conventional breakdown: two would omit a key middle layer, while four or five would imply extra categories not typically treated as primary service models.

Cloud services are commonly described in three primary service models, each offering a different level of control and responsibility. Infrastructure as a Service provides the basic building blocks—virtual machines, storage, and networking—so you manage the operating system and applications while the provider handles the hardware and virtualization layer. Platform as a Service sits on top of that, giving you a managed development and runtime environment; you focus on writing code and deploying apps, while the platform handles the operating system, middleware, and runtime. Software as a Service delivers fully ready-to-use applications accessed over the web, with maintenance, updates, and security handled by the provider. These three capture the standard spectrum from raw infrastructure to complete software solutions, which is why they’re taught as the primary classifications. The other counts don’t reflect the conventional breakdown: two would omit a key middle layer, while four or five would imply extra categories not typically treated as primary service models.