220-1101 Question 368
Single answerCommon cloud modelsA small architecture firm wants to stop maintaining an aging on-site file server and move to a cloud solution for email, file storage, and office productivity applications. The owner does not want to manage virtual machines, operating systems, or application updates, and prefers a monthly subscription per user. Which cloud model best meets these requirements?
- A
Infrastructure as a Service (IaaS)
- B
Platform as a Service (PaaS)
- C
Software as a Service (SaaS)
- D
Private cloud
Show answer and explanation
Correct answer: C
Explanation
The best answer is Software as a Service (SaaS). Common cloud service models are typically summarized as IaaS, PaaS, and SaaS. SaaS is the best fit when an organization wants to consume complete applications such as hosted email, online document editing, and cloud file storage through a web browser or client app, with the provider handling maintenance, patching, and updates. By contrast, IaaS provides raw infrastructure and still requires more IT administration, while PaaS is intended for developers building and deploying applications. Private cloud is a separate concept related to where and how cloud resources are deployed, not the level of service being consumed. This distinction is consistent with common industry guidance such as NIST cloud computing definitions and standard CompTIA A+ treatment of cloud models.
- A. Incorrect.
IaaS is incorrect because it provides core computing resources such as virtual machines, storage, and networking, but the customer is still typically responsible for managing the operating system, applications, and much of the software stack. This does not match the owner's goal of avoiding system and application administration.
- B. Incorrect.
PaaS is incorrect because it is designed primarily for application development and deployment. A provider manages the underlying infrastructure and runtime environment, but the customer still focuses on developing or maintaining applications. The scenario describes a business that wants ready-to-use email, file storage, and productivity tools, not a development platform.
- C. Correct.
SaaS is correct because it delivers fully managed software applications over the internet, usually through a subscription model. In this scenario, the firm wants cloud-based email, file storage, and office productivity applications without managing servers, operating systems, or software updates. That aligns directly with the SaaS model.
- D. Incorrect.
Private cloud is incorrect because it describes a deployment model rather than a service model, and it usually involves greater organizational control and management responsibility. While a private cloud can host services, it does not inherently satisfy the requirement for fully managed end-user applications with minimal administrative overhead.