翻译练习：计算机网络

A computer network or data network is a telecommunications network which allows nodes to share resources. In computer networks, networked computing devices exchange data with each other using a data link. The connections between nodes are established using either cable media or wireless media. The best-known computer network is the Internet.
计算机网络或数据网络就是一个允许结点共享资源的电信网络。在计算机网络里，联网计算设备彼此之间通过使用数据链路交换数据。结点之间的联系通过使用线缆介质或无线介质来建立。最有名的计算机网络就是因特网。
Network computer devices that originate, route and terminate the data are called network nodes. Nodes can include hosts such as personal computers, phones, servers as well as networking hardware. Two such devices can be said to be networked together when one device is able to exchange information with the other device, whether or not they have a direct connection to each other.
产生、路由和停止数据的计算机网络设备叫做网络结点。结点可以包括主机，比如个人电脑、手机、服务器，还有联网设备（交换机、路由器）。当一个设备能够与另一个设备交换信息时，两个那样的设备可以说成是联网了（对等网），不管它们彼此之间是否有直接联系。
Computer networks differ in the transmission medium used to carry their signals, communications protocols to organize network traffic, the network's size, topology and organizational intent.
计算机网络在以下各方面不同：用于搭载信号的传输介质（光纤、电缆、无线电波）、用于组织网络流量的通信协议、网络规模、拓扑结构（连通性）和组织意图。
differ —— different —— difference
Computer networks support an enormous number of applications and services such as access to the World Wide Web, digital video, digital audio, shared use of application and storage servers, printers, and fax machines, and use of email and instant messaging applications as well as many others.
计算机网络支持大量的应用和服务，比如访问万维网、数字视频（VOD--Video On Demand视频点播）、数字音频、共享使用应用和存储服务器、打印机、传真机、使用电子邮箱和即时通信应用（QQ-->WeXin），还有其它很多应用。
In most cases, application-specific communications protocols are layered (i.e. carried as payload) over other more general communications protocols. This formidable collection of information technology requires skilled network management to keep it all running reliably.
大多数情况下，跟应用相关的通信协议（HTTP, FTP）放在其它更通用的通信协议（TCP/IP）的上一层。这个信息技术的强大集合需要熟练的网络管理来保证网络可靠运行。