Transcript Social impact of the internet

FLUENCY WITH INFORMATION
TECNOLOGY
Skills, Concepts, and Capabilities
Tom Rebold, MPC
PART
1
Becoming Skilled At
Information Technology
Tom Rebold, MPC
3
chapter
MAKING THE CONNECTION
The Basics of Networking
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How networking has changed society
Types of communication technology
Internet addresses and DNS servers
Internet protocols
LANs vs ISPs
Internet vs WWW
File heirarchy
Tom Rebold, MPC
Social impact of the internet
• Nowhere is remote
– Alaska and New York: equal access to info
• People are more interconnected
– Instant messaging or e-mail
• Social relationships are changing
– Decline in social interactions
• English is becoming a universal language
• More freedom of speech & assembly
– Chat rooms, newsgroups, websites
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Types of communication
• Synchronous—both ends active at the
same time (telephones)
• Asynchronous—postcards, answering
machine, e-mail
• Broadcast—radio, TV
• Multicast—magazines
• Point-to-point—telephone
• The internet supports all these types (in
modified forms)
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Internet possibilities
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Synchronous—instant messaging, IP phone
Asynchronous—e-mail
Broadcast—web site
Multicast—group e-mail, newsgroup
Point-to-point—e-mail
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A diagram of the Internet
Routers
The network is a medium
just like TV or radio
Copyright © 2003 Pearson Education, Inc.
Slide 1-7
Computers connected to the
Internet are given IP addresses
IP=Internet Protocol
Domain names are easier to remember
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Slide 1-8
A domain hierarchy
A domain is a related group
of networked computers
This diagram locates:
spiff.cs.washington.edu
tracer.cs.washington.edu
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And what else?
Slide 1-9
Another View of Domains
Top level domains
(all in US)
Also many other
countries:
.uk .ca .de ...
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Slide 1-10
Hosts like Spiff make requests to a
local DNS server...(for www.mpc.edu)
DNS: domain name system
Server: a computer that
serves information
Sometimes more
than one DNS
server is queried
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DNS servers look up
the IP address of
domain name
(132.129.0.57)
Request goes to
the right IP address
Slide 1-11
The TCP/IP postcard analogy.
(Transmission Control Protocol/Internet Protocol)
Messages are broken into small units
and sent one at a time to their
destination
Like sending a novel to your publisher one postcard
at a time!
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Slide 1-12
The Internet makes use of whatever
routes are available to deliver packets.
Packets go in many
directions
They may even
arrive out of order
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Slide 1-13
A ping from the author’s machine
to eth.ch (Switzerland) makes 19 hops
The Internet is a “wide area network” (WAN)
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Slide 1-14
Computers in our laboratory are on a “local
area network” (LAN) using Ethernet
Computers listen before talking like people at a party
Robert
Metalfe’s
original
drawing of the
Ethernet
design; the
unlabeled
boxes,
computers,
“tap” onto
the wire that
Metcalfe has
labeled “The
Ether.”
Copyright © 2003 Pearson Education, Inc.
Slide 1-15
Connecting to the internet
• You can use an Internet Service Provider
(ISP) reached by modem, DSL or cablemodem
• Or use a LAN in a larger organization
(intranet) with access to the internet
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Internet vs the World Wide Web (WWW)
• Web server:
– a computer (on the internet) that sends web
pages to other computers
– Web servers and web pages together make up
the world wide web (WWW)
• To request a web page, you provide the URL
– (Uniform Resource Locator) like www.mpc.edu
– Page is sent using hypertext transfer protocol
(http://www.mpc.edu)
( http:// optional )
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Dissecting a URL
folder
folder
www.mpcfaculty.net/tom_rebold/students2/Davi
Path name to web page—
d.htmlname
Server
Tells which folders its in
And the file name
The actual page file name
David.html
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A Web page
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Slide 1-19
The HTML source that produced the previous web
page. Notice that an additional image file,
alto.jpg, is also required to display the page.
HTML
1. Takes less space
2. Lets browser
adjust image
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Slide 1-20
Directory hierarchy
A hierarchy diagram showing the path between
xerox-alto.jpg and the desktop.
Down=deeper into
tree, toward the
leaves
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Up=higher, toward
the root
Slide 1-21
Locating the web page
www.nasm.si.edu/galleries/gal100/pioneer.html
on the server www.nasm.si.edu
gal100
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Slide 1-22
Chap 3 review questions
2.
A.
B.
C.
D.
3.
A.
B.
C.
D.
English is becoming the universal language as a result of all
of the following except:
American pop culture
the dominance of science and technology in English-speaking
countries
information technology’s predominant use of English
the Alto Project
Overall, the ability of individuals to create and publish Web
pages:
presents an enormous security risk
extends human expression
has led to a proliferation of hate pages and pornographic sites
has unduly diverted huge sums from other IT projects
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Chap 3 review questions
5. If the Internet consisted of four computers, there
would be six possible connections. If it consisted of
five computers, there would be ten possible
connections. How many connections are possible
with ten computers?
A. 10
B. 30
C. 45
D. Infinite
1. eCommerce is the shortened term for _____.
3. A communication that goes out to many people
within a specific target audience is called a ______.
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