平成29年度秋期 ITパスポート試験問11

This question's explanation and your answers so far.

問11

頻出度★☆☆

SaaS の説明として，最も適切なものはどれか。

出典　平成29年度秋期 ITパスポート試験問11

解説

問 11

Incorrectア
“Providing a service for connecting to the internet” describes an ISP (Internet Service Provider) and has nothing to do with SaaS.
Incorrectイ
“Providing, as a service over a network, hardware functions of the scale needed to run a system” describes IaaS (Infrastructure as a Service). It differs from SaaS in that what it provides is hardware (servers, storage, etc.), not applications.
Incorrectウ
“In addition to hardware functions, providing over a network the platform needed to run application software, such as the OS and database” describes PaaS (Platform as a Service). It provides the foundation (platform) for development and execution, so the layer it provides differs from SaaS, which provides the functions of a finished application.
エ
正解 SaaS (Software as a Service) is a form of cloud service that provides the functions of application software over a network (the internet) — only the functions a user needs, when they are needed. Users do not need to purchase, install, or maintain the software themselves; they use the finished application directly from a browser or similar. Option エ is exactly this description, “It provides users, over a network, only the necessary functions of application software, when they are needed,” so it is correct.

ここがポイント

SaaS is one of the categories describing the scope of what a cloud service provides; it is the form that delivers the functions of the application (the finished software) itself over a network.
They are distinguished by the layer they provide: IaaS = hardware (infrastructure), PaaS = the execution platform such as the OS and database, SaaS = the application. The higher the layer, the smaller the user’s scope of management.

用語

解答問11エ