Which two service models are commonly described in cloud computing?

• A. IaaS and PaaS
• B. SaaS and DaaS
• C. IaaS and SaaS
• D. PaaS and DaaS

Answer: (A)

Cloud service models describe how responsibilities are split between the provider and you. The two commonly described primary levels are infrastructure as a service and platform as a service. In IaaS, the provider supplies virtualized hardware, storage, and networking; you decide and manage the operating system, runtimes, applications, and data. In PaaS, the provider handles the runtime environment, middleware, and underlying platform tools, while you focus on developing and deploying your applications and managing your data. This division explains why these two are highlighted: they cover the major layers from raw infrastructure up to a ready-to-use development platform. SaaS is also a common model, but it delivers finished software over the internet, with little to no control over the underlying environment, making it a higher-level offering alongside IaaS and PaaS. DaaS is more specialized and not typically listed with the main trio.