计算机专业英语教程第10章课件.ppt

第10章 Network 本章要点 What is a Network? Words and Expressions How To Do: A Search Tool How To Work：Security suites Grammar Focus：倒装句及句子种类 Text in Chinese：网络 Reading Selection: A Home (Page) of Your Own 科技英语翻译方法与技巧（Ⅲ） Practical Writing：标点符号 What is a Network? What is a Network? What is a Network? What is a Network? What is a Network? What is a Network? What is a Network? What is a Network? What is a Network? What is a Network? What is a Network? What is a Network? What is a Network? What is a Network? What is a Network? What is a Network? What is a Network? What is a Network? What is a Network? What is a Network? What is a Network? What is a Network? What is a Network? What is a Network? What is a Network? What is a Network? What is a Network? What is a Network? What is a Network? * * Throughout the world, your microcomputer can connect to other microcomputers, to the Internet, and to larger computers through the electronic communication systems. The electronic communication systems transmit information over communication lines of cable and air from one location to another. Such electronic communication lines are known as networks (Figure 10-1). A network can be arranged in several different ways to meet different users′ needs. The network arrangement is called the network′s topology. The four principal topologies are star, bus, ring, and hierarchical. In a star network, a number of small computers or peripheral devices are linked to a central unit—maybe a host computer or a file server. The host computer maintains its control by asking whether each connected device has messages to send. One advantage of the star network is that several users can share resources on a central host computer (Figure 10-2). In a bus network, there is no host computer, and instead each device in the network handles its own communication control. All communications travel along a common connecting cable called a bus and as the