计算机专业英语,主讲教师：,2,能力提高篇,3,能力提高篇,Learning Scenarios 4 Network & E-commerce,Words & Expressions Text A: Internet Text B: Introduction of Electronic Commerce Practice Reading Material,5,Words & Expressions,6,Words & Expressions,7,Words & Expressions,8,Words & Expressions,9,Text A: Internet,Based on Transmission Control Protocol/Internet Protocol (TCP/IP), the Internet that consists of Wide Area Network(WAN), Local Area Network (LAN) and the computer is an international computer network. It can provide various information resources and services for the users on the Internet. Basal functions of the Internet include: sending and receiving E-mail, issue news, Telnet, file transfer and information access. Not only is the Internet the most influential computer interconnected network, but also it is the worldwide treasure house of information resources. History of the Internet The Internet began as the ARPANET which was developed by Defense advanced Research Projects Agency (DARPA) in 1969. It was mainly used for military research. Subsequently, the Internet adopted the technology, protocols and international network of the ARPANET in its development process. In 1985, the National Science Foundation (NSF) started to build NSFNET. NSFNET gradually replaced the ARPANET and it became the backbone of research and education on the Internet. In 1989, MILNET (separated from the ARPANET) achieved connecting with the NSFNET, which named the Internet. In the early 1990s, businesses began to enter the Internet, marking the Internet started the new process of the commercialization. In 1995, NSFNET went off and the Internet was completely commercialized.,10,Text A: Internet,With a lot of companies entering the Internet, online commercial applications develop rapidly. At the same time, the Internet can provide users with more services, which makes the Internet popularization and development. In recent years, the Internet has a great development in its scale and structure, which has become a truly “global network“. Working principle of the Internet The Internet connects countless computers that have different hardware and software in different countries. In order to ensure that these computers can exchange information without encumbrance, the Internet must have a unified communications protocol (TCP/IP). When an Internet user sends a text to the others, TCP divides the text into several small data packets coupled with some specific informations in order that the receiving computer can decide that the transmission is correct. Continuous data packets can reach the same place via different routes. Routers are at the junctions of the network, which determine the optimal transmission way of the packet. Routers effectively disperse load capacity of various businesses, to avoid the system is only too busy to block. After the data packets reach their destination, the computer will remove the signs of IP, and utilize TCP for checking whether the data are losses or not during the transfer process. Based on this, it regroups the data packets into the original text. If the receiver discovers the damaged data packets, it will require the sender to resend them.,11,Text A: Internet,Gateway enables a variety of different networks to deal with the Internet by TCP/IP. Gateway can transform different protocols into TCP/IP, or transform TCP/IP into the protocols of local computer networks. Using Gateway technology can achieve connection and sharing of different protocols of the networks Today, network information has covered the whole world. Internet can immediately respond to the request of the user, which depends on the computer, gateway, router and protocol. Status of Internet applications Currently, the application of the Internet can be divided into four types in China. They are information acquisition, communication, network entertainment, business transaction. They basically cover the network news, search engines, instant messaging, blogs, online games, online music, online shopping, online payment, online finance and other specific types of applications. According to The 26th Statistical Report on Internet Development in China which published by China Internet Network Information Center, it showed that the Internet applications of Chinese netizens manifested that the degree of business had raised rapidly, the tendency to entertainment had maintained and the value of the tools of communication and information had enhanced in the first half of 2010. The performance of business application was particularly prominent. The number of netizens who visited social networking sites had reached 210 million and the use rate had been 50.1% at the end of June 2010 in China.,12,Text A: Internet,The number of new users who visited social networking sites was 34.55 million and the increase percent was 19.6%. The users of online shopping reached 140 million, and the growth rates of the users of online payment, online shopping and online banking were 30% in half y