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Chapter 2The Internet andWorld Wide Web
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Chapter 2 Objectives
Discuss how the Internet works
Understand ways to access theInternet
Identify a URL
Know how to search for information on the Web
Describe the types of Webpages
Define Webcasting
Describe the uses of electroniccommerce (e-commerce)
Identify the tools required for Web publishing
Explain how e-mail, FTP,newsgroups and message
boards, mailing lists, chat roomsand instant messaging work
Identify the rules of netiquetteRecognize how Web pages use
graphics, animation,audio,
video, and virtual realityp. 2.2
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The InternetWhat is a network?
A collection of computers anddevices connected
together viacommunicationsdevices and media
Modems
CablesTelephone linesSatellites
p. 2.2
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The InternetWhat is the Internet?
Also called the Net A worldwide collectionof networks that linksmillions of businesses,government agencies,educational institutions,
and individuals
p. 2.2
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message board
instant messaging
file transfer
e-
mailWeb
The InternetWhat are some of the services found on theInternet?
chat
p. 2.3 Fig. 2-1
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Goal:
To function even if part of the network
were disabled or
destroyed
Becamefunctional
in
September 1969
Goal:To allow scientists atdifferent locations to
share informationand work together on military and
scientific projects
History of the InternetHow did the Internet originate?
ARPANET
Networking projectby Pentagon’s
Advanced ResearchProjects Agency
(ARPA)
p. 2.3
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History of the InternetWhat is a host node?
Also called a host Any computer thatdirectly connects to a
network Often stores andtransfers data andmessages
Provides network connections for othercomputersFour original nodes on
ARPANET
University of California atLos Angeles
University of California at
Santa Barbara
University of Utah
StanfordResearchInstitute
p. 2.4
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History of the InternetWhat is NSFnet?
The National Science Foundation’s network Five supercomputer centers
Connected to ARPANET in 1986
NSFnet ARPANET
The Internet
p. 2.4
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World Wide WebConsortium (W3C)
• Oversees research andsets standards andguidelines
Internet2 (I2)• Internet-related research
and development project• Develops and tests
advanced Internet
technologies
History of the InternetWho controls the Internet?
The Internet is a public, cooperative, andindependent network No single entity controls or owns the InternetSeveral organizations advise and define standards
p. 2.4
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Technology Trailblazer Tim Berners-Lee
Created the World Wide Web
Director of the
World Wide WebConsortium(W3C) at MIT
Click to view Web Linkthen click Tim Berners-Lee
p. 2.4
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How the Internet WorksWhat is an Internet service provider (ISP)?
A business that hasa permanentInternet connection
Provides temporaryconnections toindividuals andcompanies for free
or for a fee
Regional ISP
Provides access to theInternet through one or
more telephone numberslocal to a specificgeographic location
National ISP
Provides local telephonenumbers in most major cities
and towns nationwide
May also provide a toll-freenumber p. 2.5
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How the Internet WorksWhat is a point of presence (POP)?
An accesspoint on the
Internet Accessed bydialing a
telephonenumber Select a serviceprovider with at
least one localPOP telephone
number p. 2.5
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Wireless ServiceProvider
• Company that
provides wirelessInternet access
Online ServiceProvider (OSP)
• Supplies Internetaccess
• Has many members-only features that
offer special content
How the Internet WorksWhat are other service providers?
Click to view Web Linkthen click Service Providers
p. 2.5
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Company on the CuttingEdge America Online
World’s leading online service provider Services include electronicmail, software, computersupport services,Internet access
Click to view Web Linkthen click AOL
Founded in 1985by Stephen M.Case
p. 2.6
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High speed connection• Employees and students• Computers part of a local area network (LAN)• Connect to service provider through a high-speed connection
line leased from local telephone company
How the Internet WorksHow can you connect to the Internet?
Dial-up access• Home or small business• Computer, modem, regular telephone line• Dial into an ISP or OSP
Newer high-speed technologies• Home and small business• Digital subscriber line (DSL) – provides high-speed Internet
connections over regular copper telephone line•
Cable modem- provides high-speed Internetconnections through cable television network
p. 2.6
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Backbone• Inner structure
of the Internet• Communicationslines that carrythe heaviestamount of traffic
How the Internet WorksWhat are the three parts of an Internet connection?
Server • Computer that
manages theresources on anetwork
• Provides acentralized storagearea for resourcessuch as programsand data
• Also called a hostcomputer
Client• Computer that
can access thecontents of thestorage areaon the server
Click to viewWeb Linkthen click Internet Backbone
p. 2.6
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How might data travel the Internet using a telephone lineconnection?
Step 1
How the Internet Works1: You initiate an
action to requestdata from theInternet.
p. 2.7 Fig. 2-3
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How might data travel the Internet using a telephone lineconnection?
Step 1Step 2
How the Internet Works
2: A modem convertsthe digital signalsfrom the computer into analog signals,
which areunderstood bytelephone lines.
p. 2.7 Fig. 2-3
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How might data travel the Internet using a telephone lineconnection?
Step 1 Step 2
Step 3
How the Internet Works
3: Data (request)travels throughtelephone lines to alocal ISP.
p. 2.7 Fig. 2-3
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How might data travel the Internet using a telephone lineconnection?
Step 1 Step 2
Step 3
Step 4
RegionalISP
How the Internet Works
4: Data may passthrough one or more routersbefore reaching itsfinal destination.
p. 2.7 Fig. 2-3
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How might data travel the Internet using a telephone lineconnection?
Step 1 Step 2
Step 3
Step 4
Step 5
RegionalISP
NationalISP
How the Internet Works
5: The regional ISPuses lines, leasedfrom a telephonecompany, to senddata to a nationalISP.
p. 2.7 Fig. 2-3
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How might data travel the Internet using a telephone lineconnection?
Step 1 Step 2
Step 3
Step 4Step 5
Step 6
RegionalISP
NationalISP
NationalISP
Internetbackbone
How the Internet Works
6: The national ISProutes data acrossthe country toanother national
ISP.
p. 2.7 Fig. 2-3
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How might data travel the Internet using a telephone lineconnection?
Step 1
Step 2
Step 3
Step 4
Step 5
Step 6
Step 7
RegionalISP
LocalISP
NationalISP
NationalISP
Internetbackbone
How the Internet Works
7: Data moves from anational ISP to a localISP and then to adestination server.
p. 2.7 Fig. 2-3
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How might data travel the Internet using a telephone lineconnection?
How the Internet Works
Step 1Step 2
Step 3
Step 4
Step 5
Step 6
Step 7
Step 8
RegionalISP
LocalISP
NationalISP
NationalISP
Internetbackbone
8: The server retrievesthe requested dataand sends it backthrough the Internetbackbone to your computer.
p. 2.7 Fig. 2-3
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How the Internet WorksWhat is an Internet protocol (IP) address?
Number that uniquely identifies each computer or deviceconnected to the InternetFour groups of numbers, each separated by a periodNumber in each group is between 0 to 255
IP address 199.95.72.10
first partidentifiesnetwork
last partidentifiesspecific
computer
p. 2.8 Fig. 2-4
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How the Internet WorksWhat is a domain name?
Text version of an IP addressComponents are separated by periodsEach domain name represents one or more IP addresses
IP address 199.95.72.10
Domain name www.scsite.com
p. 2.8 Fig. 2-4
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How the Internet WorksWhat is a top-level domain (TLD) abbreviation?
Identifies the type of organization associatedwith the domainSometimes called dot com when TLD is com
p. 2.8 Fig. 2-5
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Internet Corporation for AssignedNames and Numbers (ICANN)
Group that assigns and controls TLDs
How the Internet WorksWhat is systems control domain names?
Domain Name System (DNS)System on the Internet that stores the
domain names and their correspondingIP addresses DNS server
Translates the domainname into its associated IP
addressp. 2.8
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The World Wide WebWhat is a Web browser?
Also called a browserSoftwareprogram thatallows you to
access andview WebpagesTwo popular browsers for personalcomputers
• Netscape• Internet
Explorer p. 2.9 Fig. 2-6
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The World Wide WebWhat is a home page?Starting page for a browserProvidesinformationabout the site’s
purpose andcontentSome Web sitesalso refer to their
starting page asa home pageMay be changedat any time
p. 2.10
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Microbrowser for aWeb-enabledcellular telephone
The World Wide WebHow do Web-enabled handheld computers and
devices access the Web?Use a special type of browser designed fortheir small screensMicrobrowser – software programthat accesses anddisplays Web pagesthat contain mostly
text Also called aminibrowser
p. 2.11 Fig. 2-8
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The World Wide Web
What is a hyperlink? Also called a link Built-in connection
to another relatedWeb page or partof a Web page
Allows you to
obtain informationin a nonlinear wayClick to
view
animation
p. 2.12
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The World Wide WebHow can you identify a link?Link can be a word, phrase, or imageText links usually are underlined or in a colordifferent from the rest of the document
A graphical link may change its appearance when youpoint to itThe shape of the pointer onthe screen changes to asmall hand with a pointingindex finger when youposition it on a link or point to the link
p. 2.12
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The activity of jumping fromone Web page to another issurfing
The World Wide WebWhat is surfing the Web?
Links can point to an item on the same Web page, adifferent Web page at the same Web site, or aseparate Web page at a different Web site inanother city or country
p. 2.12
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The World Wide WebWhat is a Uniform Resource Locator (URL)?
Unique address for a Web pageBrowser retrieves a Web page by using the URL
Also called a Web address
http://www .nationalgeographic.com/travel/index.html
address
text boxp. 2.13 Fig. 2-10
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The World Wide WebWhat are the parts of a URL?
protocol domain name path
Click to view Web Linkthen click URLs
http://www.nationalgeographic.com/travel/index.html
p. 2.13 Fig. 2-10
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http://www.nationalgeographic.com/travel/index.html
The World Wide WebWhat is a Web server? A computer that delivers (serves)Web pages you request
p. 2.13 Fig. 2-10
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The World Wide WebWhat is a search engine? A software program you can use to find Websites, Web pages and Internet files
Search text
A word or phraseentered in the search
engine’s text box
Also called keywords
Spider
A program that readspages on Web sites in
order to find Webpages that contain the
search text
Also called a crawler
or bot
Click to
view video
p. 2.14
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The World Wide WebWhat is a hit?
Any Web page name that listsas the result of a search
hit
363 hits
p. 2.14 Fig. 2-11
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The World Wide WebWhat is a directory? An organizedset of topicsUsed by asearch engineto aid inlocating WebsitesEach majortopic hasrelatedsubtopics
p. 2.15 Fig. 2-13
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The World Wide WebWhat are the six basic types of Web pages?
advocacyWeb page
informationalWeb page
business/marketingWeb page
newsWeb page
personalWeb page
portalWeb page
p. 2.16
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The World Wide WebWhat is an advocacy Web page?
Containscontent thatdescribes acause,opinion,or ideaPurpose is toconvince thereader of thevalidity of thecause, opinion,or idea
p. 2.16 Fig. 2-14a
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The World Wide WebWhat is a business/marketing Web page?
Containscontent thatpromotes orsells products
or servicesOften allowsyou topurchaseproducts orservices online
p. 2.16 Fig. 2-14b
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The World Wide WebWhat is an informational Web page?
ContainsfactualinformationMany U.S.governmentsites provide
information
p. 2.16 Fig. 2-14c
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The World Wide WebWhat is a portal Web page
Often called aportalOffers a varietyof Internetservices from asingle,convenient
location
p. 2.16 Fig. 2-14e
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maps
stock
quotes
referencetools
sports andweather
searchengine
The World Wide WebWhat services are often found on a portal?
local ,national, andworldwide
news
freepersonalWeb pages
instantmessaging
calendars
shoppingmalls andauctions
newsgroups
or messageboards
chat rooms
p. 2.17
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The World Wide WebWhat is a Web community?
A Web site that joins a specific group of peoplewith similar interests or relationshipsUsually offer special services to facilitatecommunication among members
newsgroupor message
board e-mail onlinephoto
albumschatroomp. 2.17
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The World Wide WebWhat is a wireless portal?
A portal specifically designed fo r Web-enabled handheld comput er sand devices
Attempts to provide allinformation a wireless user mig ht requireServices include search engines,news, stock quotes, weather,maps, e-mail, calendar, instantmessaging, and shopping
p. 2.17
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Company on the Cutting
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Company on the CuttingEdge
Yahoo!Co-founded by Jerry Yang and David Filo in1994
Click to view Web Linkthen click Yahoo!
Started as a seriesof liststo organizefavorite Web sites
Today more than166 million visitorsaccess 189 millionpages dailyp. 2.17
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The World Wide WebWhat is a personal Web page? A Web pagemaintained by aprivate individualwho normally is
not associatedwith anyorganizationReasons: jobhunting andsharing lifeexperience withthe world
p. 2.17 Fig. 2-14f
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virtualreality
The World Wide WebWhat is multimedia?
Any application that integrates text with othermedia elements
graphics
audioanimation video
Often used for Web pages to add appeal
Multimedia Web pages often require moretime to download because they containlarge graphics and video or audio clips
p. 2.18
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The World Wide WebWhat is a graphic? Also called agraphical image
A digitalrepresentation of information such asa drawing, chart, orphotographFirst media used to
enhance text-basedInternet
p. 2.18 Fig. 2-15
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The World Wide Web
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GIF (GraphicsInterchange Format)
Also uses compressiontechniques to reduce filesizeWorks best for images
with only a few distinctcolors, such as linedrawings, single-color borders, and simplecartoons
The World Wide Web
JPEG (JointPhotographic Experts
Group)Graphical image that usescompression techniquesto reduce the file sizeSmaller sizes result infaster downloading of Web pageThe more compressed thefile, the smaller the file,but the lower the quality
Which two formats are most popular for the Web?
p 2 19
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