From Internet to Information Superhighway

1. 10 From Internet to Information Superhighway

2. Learning Objectives • Describe the nature of the Internet and the variety of functions it performs. • Discuss several software tools for navigating and using the Internet effectively. • Describe the evolution of the World Wide Web into a multifacted tool for entertainment, education, communication, collaboration and commerce.  2001 Prentice Hall

3. Learning Objectives • Explain how the Internet and other telecommunication technologies are evolving into an all-encompassing information infrastructure. • Discuss the future of the Internet in particular and cyberspace in general.  2001 Prentice Hall

4. Chapter Outline “It’s a bit like climbing a mountain. You don’t know how far you’ve come until you stop and look back.” Vint Cerf • The Internet: A Network of Networks • Internet Applications: Communication and Connection • Inside the World Wide Web • The Evolving Internet  2001 Prentice Hall

5. The Internet: A Network of Networks The Internet is an interconnected network of thousands of networks linking academic, research, government, and commercial institutions.  2001 Prentice Hall

6. Internet Services The Internet provides scientists, engineers, educators, students, business people, and others with a variety of services such as: • Electronic mail (send/receive mail messages) • Remote login (Telnet - access to other computers  2001 Prentice Hall

7. Internet Services • Transferring files (FTP - accessing archives of data) • Newsgroups (Usenet - on-line public discussions) • World Wide Web (a collection of multimedia documents)  2001 Prentice Hall

8. Counting Connections Today, the Internet connects computers to about every country in the world. However, the Internet is: • growing too fast to measure its growth • too decentralized to quantify • a network with no hard boundaries  2001 Prentice Hall

9. Internet Protocols The language at the heart of the Internet is TCP/IP… Transmission Control Protocol/Internet Protocol … that allows cross-network communication  2001 Prentice Hall

10. Internet Protocols • TCP breaks messages into packets • Each packet has all the information needed to travel from network to network • Host systems called Routers determine how to route transmissions  2001 Prentice Hall

11. Internet Protocols • IP is the address for the packets • Each Internet host computer has a unique IP Address • Each address is comprised of four sets of numbers separated by periods, such as 123.23.168.22  2001 Prentice Hall

12. Internet Access Options Direct (dedicated) Connection • Computer has its own IP address and is attached to a LAN • No need to dial up • Files are stored on your computer • Response time is quick  2001 Prentice Hall

13. Internet Access Options Dial-upConnections • limited connection using a modem • Full access dial up uses SLIP (Serial Line Internet Protocol) or PPP (Point-to-Point Protocol) via modem • Broadband Connections • DSL (Digital Subscriber Lines) service is newer, faster, and cheaper than ISDN (Integrated Services Digital Network) • can share phone line with voice traffic  2001 Prentice Hall

14. Internet Access Options Cable Modem Connection • allow Internet connections using shared TV cables • can exceed DSL speeds • Carry increased privacy and security risks • Satellite Connections • provides connections using DirecTV satellite dishes  2001 Prentice Hall

15. Internet Access Options Internet Service Providers (ISPs) • local ISPs provide connections through local telephone lines • national ISPs offer connections on a nationwide scale  2001 Prentice Hall

16. Intranets and Extranets Intranets: self-contained intra- organizational networks designed using the same technology as the Internet Firewalls: used to prevent unauthorized communication and secure sensitive internal data  2001 Prentice Hall

17. Intranets and Extranets Typical Intranets include: • E-mail • Newsgroups • File transfer • Web publishing • Other services  2001 Prentice Hall

18. Intranets and Extranets Extranets: designed for outside use by customers, clients, and business partners Electronic Commerce: business transactions through electronic networks  2001 Prentice Hall

19. Intranets and Extranets Electronic data interchange (EDI): a decade-old set of specifications for ordering, billing, and paying for parts and services over private networks. Virtual private networks: not subject to the traffic and security problems.  2001 Prentice Hall

20. Internet Applications:Communication and Connection • The user interface varies depending on which client/server application is being used. • UNIX- developed by Bell Labs, allows a timesharing computer to communicate with several other computers or terminals at once.  2001 Prentice Hall

21. Internet Addresses “Each person on the “Internet” has a unique e-mail “address” created by having a squirrel run across a computer keyboard.” Dave Barry • E-mail addresses are made upof two parts separated by an at(@) sign: • User name@host name • Example: johnsmith@mindspring.com • The host is named using DNS (domain name system), which translates IP addresses into a string of names.  2001 Prentice Hall

22. Internet Addresses An Internet address includes: username@hostname.sub.dom • username is the person’s “mailbox” • hostname is the name of the host computer and is followed by one or more domains separated by periods: • host.subdomain.domain • host.domain • host.subdomain.subdomain.domain  2001 Prentice Hall

23. Internet Addresses Top level domains (the last part of the address) include: • .edu - educational sites • .com - commercial sites • .gov - government sites • .mil - military sites • .net - network administration sites • .org - nonprofit organizations  2001 Prentice Hall

24. president@whitehouse.gov Internet Addresses Examples: User President whose mail is stored on the host whitehouse in the government domain User hazel_filbert at the server for Lane County, Oregon, k-12 school district hazel_filbert@lane.k12.or.us  2001 Prentice Hall

25. E-mail on the Internet What appears on the screen depends on the type of Internet connection and mail program you use Eudora is an easy to use Email software. Outlook and Netscape Communicator are popular e-mail software  2001 Prentice Hall

26. E-mail on the Internet Why are free e-mail accounts made available? • often offered to attract Web site visitors • available for users of public computers • sensible for those wanting multiple e-mail addresses not associated with a workplace Remember that security is still an issue  2001 Prentice Hall

27. E-mail on the Internet E-mail Formats include: • ASCII text so they can be viewed with any client program • MIME (Multipurpose Internet Mail Extensions)that can be used to send and receive text with enriched text or HTML (displays text formatting, graphics, and links to Web pages)  2001 Prentice Hall

28. Mailing Lists and Network News • Mailing lists allow you to participate in email discussion groups on special-interest topics. • Network News are public discussions that you can go in and out as you please. • Messages are posted on virtual bulletin boards (for everyone to read).  2001 Prentice Hall

29. Real-Time Communication • Internet relay chat (IRC)allows several users to chat simultaneously • Internet Telephony turns the Internet into a toll-free long-distance telephone service • Video teleconferences allow multi-person videoconferences via the Web  2001 Prentice Hall

30. Real-Time Communication See… …Type Hear…  2001 Prentice Hall

31. Telnet and FTP Information gathering (the most popular use of the Internet) • Telnet • makes remote login possible • FTP(file transfer protocol) • allows files to be uploaded and downloaded from remote computers  2001 Prentice Hall

32. Telnet and FTP • A friendlier face… • Web browsers locate and transfer files without typing commands • When you click a Web link to download a file, you’re probably using FTP  2001 Prentice Hall

33. Inside the World Wide Web • WWW is a distributed browsing and searching system developed at CERN • System was designed to give Internet documents unique addresses • HTML language was created for encoding and displaying documents • Browser software was built for viewing documents from remote locations  2001 Prentice Hall

34. Browsing the Web Web site Jargon: • Web pages are made up of text and images • A Web site is a collection of web pages • A Home page is the main entry to a Web site • A Web browser like Netscape Communicator or Internet Explorer allows you to explore the Web by clicking links  2001 Prentice Hall

35. Browsing the Web • Hyperlinks (links)are words or pictures that act as buttons, allowing you to go to another Web page Links are typically underlined or displayed in a different color  2001 Prentice Hall

36. More on Browsing the Web More Web site Jargon • Linksallow you to locate information without knowing its exact location (it may move from time to time) • Back and Forward buttons let you retrace your steps • Bookmarks (or Favorites) can be set up to mark your favorite Web locations  2001 Prentice Hall

37. Web Addresses Pronounced Earl…like the name Go directly to any Web destination by typing its URL(Uniform Resource Locator) A typical URL looks like this: http://www.prenhall.com.beekman  2001 Prentice Hall

38. Web Addresses The protocol used to transfer Web pages across the Net Dissecting the address The path to the resource on the host that contains the information www.vote-smart.org/ http:// help/database.html The domain name of the server containing the resource  2001 Prentice Hall

39. Searching the Web Ways to search the Web “The ability to ask the right question is more than half the battle of finding the answer.” Thomas J. Watson • Search engines • produce a list of pages that match a keyword • they are built around a database that catalogs Web locations based on content • Directoryor Subject Tree • A hierarchical catalog of Web sites • Natural Language Search Engines • Allows users to ask for what they want  2001 Prentice Hall

40. Search Engines Search engines help find information when you type a query using keywords.  2001 Prentice Hall

41. Search Engines Directory/subject tree engines offer a menu of subject choices  2001 Prentice Hall

42. Search Engines Ask questions in a Natural Language Search Engine  2001 Prentice Hall

43. Portals Portals offer quick and easy access to a variety of services such as e-mail, chat,maps, news, shopping, etc. • Examples of consumer portals include • Yahoo!, Excite, Lycos, Alta Vista, Netscape Netcenter, Snap • Specialized portals target specific industries and economic sectors  2001 Prentice Hall

44. Tables Frames Forms Downloadable audio and video Streaming audio and video Real-time live audio or video 3-D environments From Hypertext to Multimedia Typical Web pages can contain:  2001 Prentice Hall

45. Plug-Ins are software extensions that add new features. Examples include… QuickTime Shockwave/Flash RealPlayer Acrobat From Hypertext to Multimedia  2001 Prentice Hall

46. Webcasting: Push Technology “We think we ‘surf’ the Web now, but was we really do is hopscotch across fragile stepping-stones of texts…only when waves of media begin to cascade behind our screens – huge swells of unbrowsable stuff – will we truly surf.” Kevin Kelly and Gary Wolf • Client computers pull information • Browsers initiate a request for information • Push technology delivers information automatically to the client computer • Up to the minute weather reports • News headlines  2001 Prentice Hall

47. An HTML document includes codes that determines the format, layout, and structure of a Web document Publishing on the Web HTML (Hypertext Markup Language) HTML is not WYSIWYG  2001 Prentice Hall

48. Publishing on the Web This text coded as HTML … <H1>Welcome to Computer Confluence</H1><b>Publishing on the Web</b> • Appears like this on the screen …  2001 Prentice Hall

49. Publishing on the Web Alternatives to HTML… • Programs that convert document format features into HTML codes • Microsoft Word, FileMaker • Web authoring programs • HomePage, GoLive, FrontPage  2001 Prentice Hall

50. Beyond HTML Dynamic HTML: adds more programming power to HTML by allowing code to automatically modify itself under certain circumstances JavaScript:a simple language for enhancing HTML Web pages  2001 Prentice Hall