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Chapter 2
The Internet and World Wide Web
The Internet
What are some services found on the Internet?
p. 2.02 Fig. 2-1
4. Chat
(4)
(1)
1. E-mail
(2)
2. Web
(3)
3. File transfer
(5)
5. Message board
(6)
6. Instant messaging (AIM, MSN, Yahoo, ICQ)
History of the Internet
How did the Internet originate?
p. 2.02
ARPANET: Networking project by Pentagon’s Advanced Research Projects Agency (ARPA)
---To allow scientists at different locations to share information
---can function even if part of network were destroyed by a disaster
ARPANET became functional in September 1969. Four main computers: UCLA, UCSB,Stanford,UU
History of the Internet
How has the Internet grown?
p. 2.03
TodayMore than 150 million host nodes
1984More than 1,000 host nodes
1969Four host nodes
History of the Internet
Who controls the Internet?
p. 2.04
World Wide Web Consortium (W3C)
Oversees research, sets standards and guidelines
Internet2 (I2) Internet-related research
and development project
Develops and tests advanced Internet technologies
No onec—cit is a public, cooperative, andindependent network
Several organizations set standards
How can you connect to the Internet?
1. Dial-up accessmodem in your computer uses a standard telephone line
to connect to the Internet.
2. Integrated Services Digital Network (ISDN)
replaced by
3. Digital subscriber line (DSL)
provide connections using regular copper telephone lines.
4. Cable Modem
taking advantage of unused bandwidth on a cable television network.
How can you connect to the Internet?
Dial-up DSL Cable TV
Speed 56 Kbps 128 Kbps to
1.544 Mbps
200Kbps~1.5Mbps or more
Price $6~$20/
month
$20~$50/
month
$20~$50/
month
Connection Establish connection each time you log on
always on—whenever the computer is running
Evaluation Slow but inexpensive
High speed but cost about twice
as much as dial-up
http://www.ispcomparison.net/
How the Internet Works
What are the ways to access the Internet?
p. 2.06 Fig. 2-2
1. Internet Service Provider (ISP) Regional ISP: National ISP : AT&T and EarthLink provide: internet access (dial-up,DSL, cable)
2. Online Service Provider (OSP) like AOL and MSN provide: internet access and many members-only
features
3. Wireless Internet Service Provider (WISP) like AT&T wireless and Vorizon wireless provide: internet access
How the Internet Works
How might data travel the Internet using atelephone line connection?
p. 2.07 Fig. 2-3
Step 1. Request data from a server on Internet
Step 5. Regional ISP uses leased lines to send data to a national ISP
Step 6. National ISP routes data across the country
Step 8. Server sends data back to you
Step 2. Modem converts digital signals to analog signals
Step 3. Data travels through telephone lines to a local ISP
Step 4. Data passes through routers
Step 7. National ISP passes data to local ISP
What Is the World Wide Web?
The internet is a network of computer networks worldwide
The web is a tool used to retrieve information published on the internet
To navigate the web we use a browser such as Netscape or internet explorer(IE)
Internet Software: The Client-server Partnership
Two pieces of software that work together
Client: software application on user’s computer
Client retrieves, displays information for user
Server: stores and sends information to clients as requested
The World Wide Web
What is a Web browser?
p. 2.09
MicrosoftInternetExplorer Netscape
Mozilla
Program that allows you to view Web pages
Firefox
Internet Addresses
What is a URL (Uniform Resource Locator)?
p. 2.10 Fig. 2-8
Unique address for a Web page
A web server delivers the Web page to your computer
The World Wide Web
What is downloading?
p. 2.10
The process of a computer receiving information Depending upon connection speed, downloading can
take from a few seconds to several minutes
The World Wide Web
How can you establish a connection and start theWeb browser?
p. 2.09 Fig. 2-6
Step 2.If necessary, connect to the Internet
Step 3.Connection to the Internet occurs, and a home page displays
Step 1.Click the Web browser program name
The World Wide Web
How do handheld computers and cellular telephones access the Web?
p. 2.10 Fig. 2-7
Must be Web-enabled
Use a microbrowser that displays Web pages that contain mostly text
How the Internet Works
What is a domain name?
p. 2.08 Figs. 2-4 – 2-5
Text version of Internet protocol (IP) address Number that uniquely identifies
each computer or device connected to Internet
Domain name:www.google.com
IP: 64.233.161.99
Keeping the Web Straight: Document Addresses
Address format: Eg., Http://www.cs.gsu.edu/~xfu1/1010.html
Address must be exact, i.e. Upper and lower case letters make a difference
.Edu, .Com, .Org, .Gov, ~
HTTP: hypertext transfer protocol Document type for all web documents
HTML: hypertext markup language Language for creating web documents
How to Check your IP address
p. 2.08 Figs. 2-4 – 2-5
Check your own IP address• Start ---all programs ---Accessories—Command Prompt
• Type “ ipconfig /all”.
Check what is the IP address• Start ---all programs ---Accessories—Command Prompt• Type “ping www.google.com”
Hypertext Links
Highlighted words or text in a WWW document
Moves you to a place within same document, or to a web page elsewhere
Previous page
www.student.gsu.edu/~xfu1/1010.html
What Is a Web Site?
http://www.library.utoronto.ca
an electronic document stored on a web server
uses HTML (Hypertext Markup Language)
may include text, sound, animation, images
usually has links to other Web pages or different parts of the same Web site
What Is a Home Page?
The first web page you see when you access a web site
Usually provides means of moving to other areas at that web site (directory, table of contents)
Who Provides Internet Information?
Non-profit: governments, universities, libraries, non-profit groups
Commercial information providers
Self-publishers (personal home pages)
Only a fraction of what is available is on the web
Using the World Wide Web
• Allows you to browse a wide variety of internet sources
• Instantaneous connections to internet sites world wide
Advantages Disadvantages• Connections can be slow or busy• No standard methods of
organization• Out-of -date materials may not be
removed• Contents can be (maliciously) altered• Sites can simply be moved/removed
What Affects the Speed of Transmission?
Phone lines are “slower” than ethernet wiresSpeed of modem: speed of data transmission (BPS)Modems transmit at 28,800, 33,600 and 56k baud
Traffic on the internet The power of your PC The data being transmitted
Error Messages Do Happen
An error message can appear in a window on your screen,
becauseThe URL may be incorrectThe site may have “moved”The communication lines may be busy
SO retype the URL or try again later
IE Menu Bar
FILE: for working with files (similar to word processing)
EDIT: for editing page content and setting preferences
VIEW: for options on viewing page content
Favorites: Save your favorite websites
Tools: configuration your IE
HELP:
IE Toolbar = Quick Navigation
Back and Forward - for short jaunts
Refresh - get current page again
Home - go back to the first screen that appears after logging on
Search - access to internet search engines
History-the web sites visited before
back forwardrefresh home history
Tool bar customize:1. Let the mouse point to
toolbar 2. click right button of
mouse3. Click “customize..”
Assignment 1
Satisfying the requirement Concise and clear description and explanation
A Brief Word on Searching
There are four main ways to find information on the internet:
Using an address (URL)
Net surfing (jumping from link to link)
Using subject directories like yahoo
Using search engines like Google
Try Searching
Search engines:
1. Open http://www.google.com2. Click “Advanced Search ”3. Input “computer”,
-- Any Web site name that is listed as the result of a search
What is a hit?
The World Wide Web
What is a search engine? Program used to find
Web sites and Web pages by entering words or phrases called search text Also called a keyword
The World Wide Web
What is a subject directory? Search tool with organized set of topics and subtopics Lets you find information by clicking links rather than
entering keywords
The World Wide Web
What are the eight basic types of Web sites?
Portal News Informational Business/marketing Educational Entertainment Advocacy Personal
The World Wide Web
What is a portal?
A Web site that offers a variety of services from one, convenient location, usually for free
Searching, sports, e-mail, news, weather, auctions,
Example:
1. open “maps.yahoo.com”
2. Click “Driving Directions”
3. In A,
Input “34 peachtree street”
Input “atlanta,30303”
4. In B,
Input your home address
The World Wide Web
What is a news Web site? Contains newsworthy material Stories and articles relating to current events, life,
money, sports, and weather
The World Wide Web
What is an informational Web site? Contains factual information Created by organizations and government agencies
The World Wide Web
What is a business/marketing Web site? Contains content that promotes products Allows you to purchase products or services online
The World Wide Web
What is an educational Web site?
Some companies offer online training for employees
Some colleges offer online classes and degrees
Offers avenues for formal and informal teachingand learning
The World Wide Web
What is an entertainment Web site? Offers an interactive environment featuring music,
video, sports, games, and more
The World Wide Web
What is an advocacy Web site? Contains content that describes a cause, opinion,
or idea
The World Wide Web
What is a personal Web site? Web page maintained by private individual Reasons: sharing life experience with the world
or job hunting
The World Wide Web
What is multimedia? Application integrating text with other media elements
Graphics Animation Audio Video Virtual reality
The World Wide Web
What graphics formats are used on the Web?
BMPBMP
GIF(pronounced JIFF)
GIF(pronounced JIFF)
JPEG or JPG(pronounced JAY-peg)
JPEG or JPG(pronounced JAY-peg)
PCXPCX
PNG(pronounced ping)
PNG(pronounced ping)
TIFFTIFF
The World Wide Web
What is a thumbnail? Small version of a larger
graphic imagec—used to improve Web page display time Usually click
on thumbnail to display larger image
The World Wide Web
What is audio? Music, speech, or any other sound
Individual compressed sound files that you download from the Web to your computer
Common Web audio file formats are MP3, WAV, WMA (Windows Media Audio), MPEG, RealAudio, and QuickTime
Once downloaded, you can play (listen to) the contents of the files
The World Wide Web
What is streaming audio?
Transfers data in a continuous and even flow
Enables you to listen to the sound as it downloads to your computer
Radio stations use streaming audio to broadcast over the Web
The World Wide Web
What is video? Consists of full-motion images with sound
played back at various speeds MPEG (Moving Pictures Experts Group)
is popular video compressionstandard
The World Wide Web
What is virtual reality (VR)? Use of computers to simulate real or imagined
environment Appears as a three dimensional (3-D) space
Used for games and many practical applications
The World Wide Web
What are plug-ins? Programs that
extend the capability of a browser
You can download many plug-ins at nocost from variousWeb sites
Plug-in Application Web Address
Acrobat Reader www.adobe.com
Flash Player macromedia.com
Liquid Player liquidaudio.com
QuickTime apple.com
RealOne Player real.com
Shockwave Player macromedia.com
Windows Media Player microsoft.com
Business to business (B2B)Business providing goods and
services to other businesses
Consumer to consumer (C2C)One consumer sells directly to another
Electronic Commerce
What is e-commerce?
Business to consumer (B2C)Sale of goods to general public
Short for electronic commerce Business transaction that occurs over
the Internet
Other Internet Services
What is e-mail? Short for electronic mail The transmission of messages and files via a computer
network Messages can consist of simple text or can contain attachments,
such as documents, graphics, or audio/video clips Internet access providers usually provide an e-mail program Some Web sites—such as MSN Hotmail and Yahoo!—provide
free e-mail services One of the original services on the Internet
Other Internet Services
How do you send an e-mail message?
Step 1.Start an e-mail program (Microsoft Outlook, for example)
Step 2.Click the New Mail Message button
Step 3.Enter the recipient’s e-mail address, the subject, and the message
Step 4.Click the Insert file button if you want to attach a picture, for example, and click Send
Step 5.The recipient opens the message
Other Internet Services
How does an e-mail message travel?Step 1.Using e-mail software, you create and send message
Step 2.Your software contacts software on your ISP’s outgoing mail server
Step 4.When recipient uses e-mail software to check for e-mail messages, the message transfers from incoming mail server to recipient’s computer
Step 3.Software on outgoing mail server determines best route for data and sends message, which travels along Internet routers to recipient’s incoming mail server
Other Internet Services
What is a mailing list? Group of e-mail addresses
given a single name
When a message is sent to the mailing list, everyone on the list receives the message
To add your name to a mailing list you must subscribe to it; to remove your name you must unsubscribe
Other Internet Services
What is FTP? File Transfer Protocol—Internet standard that allows
you to upload and download files with other computers on the Internet
Netiquette
What is netiquette?
Golden Rule: Treat others as you would like them to treat you.
Code of acceptable behaviors users should follow while on the Internet
Web Publishing
What is Web publishing?
Step 1.Plan the Web site
Step 2.Analyze and design the Web site
Step 3.Create the Web site
Step 4.Deploy the Web site
Step 5.Maintain the Web site
Development and maintenance of Web pages
Summary of the Internet and World Wide Web
History of the InternetHistory of the Internet
How to access and connect to the Internet
How to access and connect to the Internet
The World Wide WebThe World Wide Web
Electronic commerceElectronic commerce
Other Internet servicesOther Internet services
NetiquetteNetiquette
Web publishingWeb publishing
Chapter 2 Complete
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