220-1101 Question 374
Single answerSoftware as a service (SaaS)A small accounting firm wants to replace a locally installed invoicing application with a solution that employees can access from office PCs, home laptops, and mobile devices without the IT technician installing or updating the software on each device. The owner also wants the vendor to handle application maintenance and feature updates. Which service model best meets these requirements?
- A
Software as a service (SaaS)
- B
Infrastructure as a service (IaaS)
- C
Platform as a service (PaaS)
- D
On-premises virtualization
Show answer and explanation
Correct answer: A
Explanation
The best answer is Software as a service (SaaS). In CompTIA A+ Core 1, SaaS is understood as a cloud model in which users consume a completed software application that is hosted and maintained by the provider. This is ideal when an organization wants broad device access, minimal local installation, and centralized vendor-managed updates. By contrast, IaaS supplies raw infrastructure resources, and PaaS supplies a development platform rather than a finished end-user application. On-premises virtualization can improve local resource usage, but it does not shift application maintenance to the vendor. This aligns with common cloud service model definitions published by NIST, where SaaS enables use of the provider's applications running on a cloud infrastructure.
- A. Correct.
Correct. SaaS delivers fully managed applications over the internet, typically through a web browser or thin client. In this scenario, the invoicing software is accessed from multiple device types without per-device installation, and the provider is responsible for maintaining the application and rolling out updates. This matches the core SaaS model used by many business productivity and line-of-business applications.
- B. Incorrect.
Incorrect. IaaS provides fundamental computing resources such as virtual machines, storage, and networking. With IaaS, the customer is still typically responsible for installing, configuring, and maintaining the operating system and applications. That does not meet the requirement for the vendor to handle the application itself.
- C. Incorrect.
Incorrect. PaaS provides a platform for developers to build, test, and deploy applications without managing the underlying infrastructure. It is useful for application development, but it does not describe a finished invoicing application being consumed directly by end users as a fully managed service.
- D. Incorrect.
Incorrect. On-premises virtualization allows an organization to run multiple virtual machines on local hardware, but the business would still be responsible for hosting, updating, and maintaining the invoicing application environment. This is the opposite of the stated goal of reducing local installation and maintenance.