Cloud computing is a phrase used to describe a variety of computing concepts that involve a large number of computers（ ） through a real-time communication network such as the Internet. In science, cloud computing is a （ ） for distributed computing over a network, and means the（ ） to run a program or application on many connected computers at the same time. The architecture of a cloud is developed at three layers: infrastructure, platform, and application. The infrastucture layer is built with virtualized computestorageand network resources. The platform lay-er is for general-purpose and repeated usage of the collection of software resources. The application layer is formed with a collection of all needed software modules for SaaS applications. The infrastucture layer serves as the（ 此空作答 ） for building the platform layer of the cloud. In turn, the platform layer is founda-tion for implementing the （ ) layer for SaaS application
- A.network
- B.foundation
- C.software
- D.hardware
正确答案及解析
正确答案
解析
云计算是一个用来描述各种计算概念的一个短语，计算概念涉及大量计算机通过实时通信的网络，如Internet ，连接在一起。在科学研究中，云计算是分布式网络计算的同义词，意味着有能力同时在多台互连的计算机上运行一个程序或应用。云的结构分为3层：基础设施、平台和应用。基础实施层由虚拟计算机存储和网络资源构成；平台层是具有通用性和复用性的软件资源的集合；应用层是云上针对SaaS应用的所有应用软件的集合。基础设施层时建立平台层的硬件基础；相应地，平台层是执行应用层SaaS应用的基础。
