《计算机专业英语》谢希仁第二版-第8章讲义

Chapter 8 The Internet

Requirements: 了解Internet的起源 掌握Internet的关键技术概念 描述 Internet协议与应用程序的作用 解释当前Internet的结构 理解当前Internet的局限 描述Internet II的潜在作用

What is the Internet? Where did it come from, and how did it support the growth of the World Wide Web? What are the Internet’s most important operating principles? The Internet is an interconnected network of thousands of networks and millions of computers (sometimes called host computers or just hosts) linking businesses, educational institutions, government agencies, and inpiduals together. 因特网是什么? 它来自何处，和它如何支持万维网的增长? 因特 网最重要的运行原则是什么?因特网是成千上万的网络和数以百 万计的计算机(有时被称为主机计算机或主机)将企业、教育机构、 政府机关和个人联结起来的一个互联网络。

The Internet provides around 400 million people around the world (and over 170 million people in the United States) with services such as e-mail, newsgroups, shopping, research, instant messaging, music, videos, and news. No one organization controls the Internet or how it functions, nor is it owned by anybody, yet it has provided the infrastructure for a transformation in commerce, scientific research, and culture. 因特网为全球大约4亿人(其中美国1.7亿多人)提供诸如电子邮件、 新闻讨论组、购物、研究、即时信息、音乐、视频和新闻等服务。 没有任何组织控制因特网或它的运作,它也不被任何人所拥有,尽 管它为商业交易、科学研究和文化提供基础设施。

The word Internet is derived from the word internetwork or the connecting together of two or more computer networks. The World Wide Web, or Web for short, is one of the Internet’s most popular services, providing access to over one billion Web pages, which are documents created in a programming language called HTML and which can contain text, graphics, audio, video, and other objects, as well as “hyperlinks” that permit a user to jump easily from one page to another. 因特网(Internet)一词起源于互联网络(internetwork)或两个或更 多的计算机网络联接在一起。全球信息网,或简称万维网,是因特 网上最流行的服务之一,提供对10亿多网页的访问，这些网页是 由一种叫做HTML(超文本链接标示语言)编程语言生成的文件， 它可以包含本文、图形、声频、视频和其他对象、以及允许用户 容易地跳跃到其他网页的“超链接”。

8.1 The Internet: Key Technology ConceptsNew Words & Expressionshyperlink n.[计]超链接 audio adj. n. 音频 video adj. n. 视频 quadrillion n.千的五次方, adj.千之五次方的 megabyte n.[计]兆字节 protocol n.草案, 协议 quad n. 四元组 mainframe n.[计]主机, 大型机 vulnerable adj.易受攻击的, 易受...的

攻击 Domain Name 域名 gigabyte n.十亿字节(giga-为字首,―十亿”) supercomputer n.[计] 超级计算机 host computer (host) 主机 instant messaging 即时信息服务 packet-switching 分组交换技术 client/server 客户机/服务器 circuit switching 线路转接 bit n.[计]位, 比特 Router [计] 路由器 routing algorithm 路径算法 Ethernet n.以太网 backup vt.做备份; adj. [计] 文件备份

8.1 The Internet: Key Technology ConceptsAbbreviationsTCP (Transfer Control Protocol) 传输控制协议 IP(Internet Protocol) 网际协议 URL (Uniform Resource Locator) 统一资源定位 DNS (domain name system) 域名系统 RAM (random access memory) 随机存储器 IP address IP地址 ICANN (Internet Corporation for Assigned Names and Numbers) 因特网域 名与地址管理组织

8.1 The Internet: Key Technology ConceptsIn 1995, the Federal Networking Council (FNC) took the step of passing a resolution formally defining the term Internet. ―Internet‖ refers to the global information system that— I. is logically linked together by a globally unique address space based on the Internet Protocol (IP) or its subsequent extensions/follow-ons; 在 1995 年，联邦的网络委员会(FNC)通过了一个关于因特网 术语正式定义的决议。 “因特网”是这样的全球信息系统—— I. 通过以因特网协议或其扩展或继续为基础的、独特的地 址空间被逻辑性地联结起来；

8.1 The Internet: Key Technology ConceptsII. is able to support communications using the Transmission Control Protocol/Internet Protocol (TCP/IP) suite or its subsequent extensions/follow-ons, and/or other IP-compatible protocols; and III. provides, uses or makes accessible, either publicly or privately, high level services layered on the communications and related infrastructure described herein. II.能够支持使用TCP/IP(传输控制协议/因特网协议)组或其 扩展/继续、和/或其他与IP协议(因特网协议)兼容的协 议进行的通信；并且 III.提供、使用或使可访问此处描述的通信及其相关基础 设施(不论公用的还是专用的)上分层次的高水平服务。

8.1 The Internet: Key Technology ConceptsBased on the definition, the Internet means a network that uses the IP addressing scheme, supports the Transmission Control Protocol (TCP), and makes services available to users much like a telephone system makes voice and data services available to the public. 基于这个定义，因特网表示这样一个网络——使用IP地址分配 方案、支持传输控制协议，并使用户可以使用多种服务——与 电话系统使公众能够使用声音和数据服务非常类似。

8.1 The Internet: Key Technology ConceptsBehind this formal definition are three extremely important concepts that are the basis for understanding the Internet: packet switching, the TCP/IP communications protocol, and client/server computing. Although the Internet has evo

lved and changed dramatically in the last 30 years, these three concepts are at the core of how the Internet functions today and are the foundation for Internet tomorrow. 在这个正式的定义背后，隐含着三个极其重要的概念:分组交 换、TCP/IP(传输控制协议/网际协议)通信协议和客户机/服务 器计算技术，它们乃是理解因特网的基础。尽管因特网在过去 30年发生了引人注目的进化和变化，但这三个概念仍是今天因 特网运转的核心，也是未来因特网的基础。

8.1 The Internet: Key Technology ConceptsPacket Switching. Packet switching is a method of slicing digital messages into parcels called ―packets,‖ sending the packets along different communication paths as (while) they become available, and then reassembling the packets once they arrive at their destination. Prior to (before) th …… 此处隐藏：6452字，全部文档内容请下载后查看。喜欢就下载吧 ……