A development team wants to ship a web application without patching operating systems or managing scaling servers. Which statement correctly contrasts PaaS and IaaS?
Show answer and explanation
Answer: A
Platform as a Service takes responsibility for the operating system, runtime, and much of the scaling layer, so developers focus on application code. Infrastructure as a Service supplies virtual machines, storage, and networks, and the customer manages the operating system, middleware, and applications on top. The two models differ in how much of the stack the provider runs.
Why the other options are wrong
- B. This reverses the responsibilities. IaaS leaves application deployment and server patching to the customer, while PaaS handles those tasks for developers.
- C. Customers never get access to the physical hypervisor in either model. The provider runs that layer, and PaaS in particular hides the underlying machines.
- D. The models differ in what the provider manages, not just billing. IaaS gives control of the operating system, while PaaS abstracts it away.