Internet Also called Inter-connected network Internetworking
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
History of Internet 1977TCP/IP (Transmission Control Protocol/Internet Protocol) 1986NSFNET 1991WAIS (Wide Area Information Servers) - Gopher * text-base information * in UNIXenvironment
History of Internet 1992WWW 1993Mosaic - the first WWW graphical browser 1994Netscape - multi-media information/hypermedia information -Windows environment
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
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)
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
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
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
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
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
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
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
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
Basic requirement for subscription of internet services computer modem telephone line ISP description –utilities programs –user name, pasword, e_mail address Others –windows
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
Common Search Engines Yahoo Infoseek Lycos Excite etc..
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
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
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.
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
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
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.
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