Internet

1. Internet Internet Resources

2. Internet Also called • Inter-connected network • Internetworking

3. History of Internet • 1969 Advanced Research Project Agency Network (ARPANET) under the Department of U. S. Defense • Aims • maintain communication in case of a nuclear war • share information • discuss topics of interest • research various subjects

4. History of Internet • 1977 TCP/IP (Transmission Control Protocol/Internet Protocol) • 1986 NSFNET • 1991 WAIS (Wide Area Information Servers) - Gopher * text-base information * in UNIX environment

5. History of Internet • 1992 WWW • 1993 Mosaic - the first WWW graphical browser • 1994 Netscape - multi-media information/hypermedia information -Windows environment

6. Why “on the Internet”? • freedom • no “Internet” company • no board of directors, no bosses • no official censors • bargain • doesn’t charge for anything • belongs to everyone • not dependent upon proximity

7. Internet Resources • Worldwide Web (WWW) • Newsgroup(Usenet) • Bulletin Board System (BBS) • Electronic Mail (E_mail) • Conversation over the Internet (Chat) • Remote Logon (Telnet) • File Transfer Protocol (FTP)

8. World Wide Web (WWW) • also called Web, WWW or W3 • a part of the Internet • a system that enables users to find and retrieve information by navigating through linked hypertext documents • a huge collection of documents stored on computers around the world

9. Terminology : WWW • Web Page • a document on the Web • include text, pictures, sound and video • Web Site • a collection of Web pages • always maintained by a college, university, government, company or individual

10. Characteristics of WWW • Hypertext • text is interlaced with links that allow to read information not only in a linear fashion but easily jump to new entry point • Hypermedia • links point to information either be textual, graphical, sound or movies

11. Characteristics of WWW • Graphical • browsers are best at displaying graphical contents • Cross-platform • Global & Distributed • links point to information anywhere on the internet • Dynamic • information is easy to update • Interactive

12. 3 set of rules in WWW • HTML (Hypertext Markup Language) • ordinary text files including tags that control the appearance of the file. • tags can also define a word or phrase as a link • users need a web browser program to view web pages

13. 3 set of rules in WWW • HTTP (Hypertext Transport Protocol) • allows a networked computer to listen for and respond to incoming requests for files • URL (Uniform Resource Locator) • URL is the Internet address for a web document or other file • users can retrieve documents either by • manually entering URL • selecting links that contains a URL

14. Guideline for surfing the Internet • hands-on experience is essential • accompany the students to find interesting user-friendly sites • bookmark the favorite WWW sites • consider setting limits on the amount of time per day to spend on the Internet

15. Guideline for surfing the Internet • If the students do surf by themselves, check up on them once in a while • advise your students never give out their name, address, phone number, photos to anyone on-line without first consulting the teacher/parent • Internet is similar to the rest of the world. Use common sense as one would on the street

16. Basic requirement for subscription of internet services • computer • modem • telephone line • ISP description • utilities programs • user name, pasword, e_mail address • Others • windows

17. Some common Web Browsers • Browser is a program that let you view and explore in formation on the Web • For example • Mosaic • Netscape Navigator • Internet Explorer

18. Common Search Engines • Yahoo • Infoseek • Lycos • Excite • etc..

19. News/Discussion groups • USENET is a system of discussion groups • It is free of charges • It offers bulletin boards, chat rooms and network news • Join the group for • reading some particular articles • discussing topics of interest • seeking for advice of certain problems

20. Bulletin Board System (BBS) • an electronic bulletin board computer system provides places for posting articles, which are used to • distribute information • express opinions • seek for advice • reply to an article

21. Conversation over the Internet (Chat) • Using the same chat system, Conversation can be made • between 2 persons • among a group of people • to the public • It can communicate text messages back and forth, if microphone and sound capability are available, actual voice conversation can be performed.

22. Electronic Mail (E_mail) • Electronic message transfer between two users through the Internet • Messages include text, pictures, recorded voice • Transmission rate is very fast • An e_mail address is needed for sending

23. Gopher • a part of the Internet that categorizes information in menus; separated from the WWW • a menu-based program that enables users to browse for information on the Internet • allows you to search a lists of resources and then helps to send the material to you

24. Telnet • A telnet can be made if an account exists in the remote computer,and a connection is made through Internet with the provision of correct username and password • Users are allowed to login any remote computers around the world. Computer used for telnet becomes a terminal for the remote computers • Services provided by remote computers can be accessible at any other places.

25. File Transfer Protocol(FTP) • allowing file transfer from point to point through Internet • you may upload their HTML documents to the Internet for your own Web page • you may download any shareware/freeware distributed by software developer for trialfrom the remote computer