The Internet: A Resource for All of Us

1
The InternetA Resource for All of Us

• Chapter 8

2
Objectives

• Briefly describe the history of the Internet
• Explain what is needed to get on the Internet
• Describe generally what an Internet service
  provider does
• Describe the rudimentary functions of a browser
• Describe how to search the Internet
• List and describe the non-Web parts of the
  Internet
• Explain some of the ongoing problems associated
  with the Internet

3
Contents

• History of the Internet
• URL
• Getting Started
• Internet Service Provider
• Browser
• Browser Support
• Moving Between Sites
• Searching the Internet
• Other Uses of the Internet
• Internet Issues

4
History of the Internet

• Government and Universities over 30 years
• Whos connected today?
• Individuals
• Educational institutions
• Government
• Research
• Medical
• Businesses
• Everyone!

5
ARPANetAdvanced Research Projects Agency Network

• 1969 US Department of Defense and Rand
  Corporation
• Origins
• Cold War fear that a bomb could demolish
  computing capabilities
• Several computers, geographically dispersed,
  networked together
• Plan if one computer was disabled, others could
  carry on using alternative communication routes

6
ARPANetTransmitting the Message

• Messages divided into packets
• TCP/IP protocol
• TCP does the packeting and reassembling of the
  message
• IP handles the addressing

7
ARPANetExpands Beyond the Military

• Research computers from universities
• Defense contractors
• Needed technical expertise to work on Internet

8
Tim Berners-Lee

• 1990
• Perceived a spiders web of computers with links
  from computer to computer
• CERN site
• Dr. Berners-Lees physics laboratory
• Birthplace of the World Wide Web
• Easy movement due to links
• Hypertext
• Hyper-region

9
Marc Andreessen

• 1993
• Created browser software
• Mosaic first browser
• Provided attractive images and a graphical
  interface permitting users to click on pictures
  as well as text

10
ARPANet to Internet

• TCP/IP software is public domain
• Network became more valuable as it embraced other
  networks
• ARPANet disappears

11
Internet Explosion

• Mid 1990s
• Estimate over 333 million users worldwide
• Part of our daily lives
• Four factors
• TCP/IP standard
• Ability to link from site to site
• Ease of use of browser
• Growth of PC and LANs that can connect

12
URLUniform Resource Locator
http//domain-name.top-level-domain/last-section

• Unique address of a web page or file on the
  Internet
• Case-sensitive

13
httphypertext transfer protocol
http//domain-name.top-level-domain/last-section

• Protocol rules
• Communication using links

14
Domain name
http//domain-name.top-level-domain/last-section

• Address of the ISP
• Domain names are registered
• Ongoing fee is paid for each domain name

15
Top-level Domain

• Represent the purpose of the organization of
  entity
• .com
• .gov
• .edu
• .org
• .net
• May be a two-letter country code

16
Last section
http//domain-name.top-level-domain/last-section

• Directories and file names that specify a
  particular web page

17
Getting Started

• Computer with a modem or NIC
• Internet service provider (ISP)
• Browser
• Related software

18
Internet Service Provider

• Vehicle to access the Internet
• Provides
• Server computer
• Software to connect

19
Online service

• ISP
• Members-only services and information
• Simple interface with clickable topics
• Parent controls

20
Wireless Internet Access

• Supports mobile handheld devices
• Text pagers
• PDAs
• Pocket computers
• Web-enabled cellular phones
• Applications
• E-mail
• Checking weather
• Making airline reservations

21
Wireless Internet Access

• Need
• Account with wireless access provider
• Cellular modem card or adapter
• Wireless Application Protocol (WAP)
• Convert web pages into format for mobile devices
• Resized for limited display area
• Fewer graphics transmitted
• Slow download speeds

22
Browser

• Netscape Communicator
• Microsoft Internet Explorer

23
Browser

• Used to explore the Internet
• Dials the ISP
• Display web pages

24
BrowserParts of the screen
25
BrowserFunctions and Features

• Browser display window
• Displays contents of web page from each Internet
  site visited
• Screen limits how much of the site you can view
  at a time. The page can be scrolled using the
  scroll bar to see its entire contents
• Status line progress of data being transferred
  and other messages

26
BrowserFunctions and Features

• Welcome banner on title bar
• Browser logo animation indicates you are in the
  process of moving to a new site
• Hot list
• Bookmark
• Favorites
• Store your favorite URLs
• Browser control panel menus and buttons

27
BrowserMenus and Buttons

• Pull-down menu
• Buttons
• Convenient shortcuts for commonly used functions
• Click button rather than locate command from
  pull-down menu

28
Browser SupportFrames

• Divides page into rectangular sections
• Each section displays web pages independently
• Several small pages on one screen
• Can be scrolled independently
• Can be replaced with other pages independently

29
Plug-ins

• Software that increases the functionality of a
  browser
• Audio-video
• Image viewing
• Download from web sites
• Install
• Example
• Adobe Acrobat Reader
• Shockwave

30
Programming

• Java
• Write software that is machine independent
• Programming language
• Dancing icons
• Sound clips
• Flashing messages
• Banners that scroll
• Applets Permits dynamic web pages
• Display animations
• Receive input
• Perform calculations

31
Programming

• ActiveX Controls
• Capabilities similar to Java
• Browser must be enabled to support applets /
  ActiveX Controls
• Security issues

32
Moving Between Sites

• Clickable categories in the browser
• Sports
• Weather
• News
• Technology
• Comic strips
• Enter the URL in the address text box and press
  ltEntergt

33
Processing RequestsURL

• User enters a URL
• User computer sends request to the ISP server
• ISP server sends request across networks of
  TCP/IP computers
• Destination site is reached
• Content is transmitted back to your computer
  (process in reverse)

34
Searching the Internet

• Search engine
• User specifies a search request
• Browser links to Search Engine
• Request returns matching pages based upon the
  Search Engines database
• Results presented

35
Processing RequestsSearch Engine Database

• Search Engine builds database
• Searchable terms
• Related web sites
• Spider, robot, bot
• Follows links across the web
• Automatically indexes pages to a database
• One word
• All words
• Pages may be submitted by the owner

36
Processing RequestsSearch Engine Database

• Request same search using different engines
  yields different results
• Databases built independently
• Size
• Content
• Search methodology
• Metasearch atomically puts the same request to
  several search engines

37
Processing RequestsDirectory vs. Search Engine

• Directory
• Human involvement
• Sites organized by content category
• May concentrate on specific content areas
• Subjective decisions regarding inclusion and
  importance
• Search Engine
• Spider, robot, or bot automatically builds
  database
• Index on a few keywords
• Index on all words on web page

38
Processing RequestsSearch Engine Limitations

• Index only a fraction of the Web
• Approximately 20 to 33 of sites
• More web pages added daily
• Solution
• Same request to several search engines
• Metasearch

39
Search Tools

• Directories
• Yahoo!
• NetGuide
• Metasearch Sites
• MetaCrawler
• Dogpile

• Search Engines
• AltaVista
• Excite
• Google
• HotBot
• Infoseek
• Lycos
• Northern Light

40
Refine the Search

• Add words
• Enclose words in quotes
• Use Boolean logic
• Examples
• World Trade Center
• Jordan AND NOT Michael

41
Other Uses of the Internet

• Newsgroups
• FTP
• Telnet
• E-mail
• Internet Relay Chat (IRC)

42
Newsgroups / Usenet

• Large bulletin board divided by category
• Posting and reading of messages that focus on
  specific topics
• Over 20,000 newsgroups
• Functions
• Conversation
• File download
• Newsreader software required (included with most
  browsers)

43
Newsgroup Operations

• Lurking
• Posting material
• Inappropriate material
• Flame
• Flame war
• Moderated newsgroup

44
FTPFile Transfer Protocol

• Download files to your local computer
• Upload files to another computer
• Requirements to download file
• Permission to download from a site
• File is available for copying
• Anonymous FTP do not need to identify yourself
  to the remote computer

45
Public Archives
Sounds
Images
Graphics
Programs
Text

• Free files provided by educational institution or
  the government

46
Telnet

• Use your PC as a terminal providing remote access
  to another computer
• Permits
• Log on to a host
• Use as if you are sitting at a local terminal
• Need account on the host system
• Telnet software required (provided with most
  browsers)

47
e-mail

• Send/receive written messages
• Most used feature of the Internet
• Mail server Collects and stores e-mail
• Mailbox Assigned to each user
• E-mail address
• User name
• _at_
• Domain of the mail server

48
e-mailClient Software Functions

• Retrieve
• Create
• Send
• Store

• Print
• Delete
• Address book
• Attach files
• Filters

49
IRCInternet Relay Chat
50
Not Quite Perfect Yet

• Unregulated
• Useless web sites
• Misinformation and misstatements on web sites
• Concern over government censorship

51
Not Quite Perfect YetSocial Issues

• Behavior problems
• Who is out there?
• What are they doing?
• Netiquette
• Suggestions for appropriate behavior
• Example TYPING IN CAPS is shouting

52
(No Transcript)