Discovering Computers 2008
Chapter 2
The Internet and
World Wide Web
Defining the Internet
The Internet is a collection of ________
________ that are used for
________ and _______ communications
and for ________ exchange.
The Internet
What are some services found on the Internet?
E-mail
Web
File transfer
1.
2.
3.
4.
5.
6.
Chat
Message board
Instant messaging
(1)
(3)
(2)
p. 68 Fig. 2-1
(4)
(5)
(6)
Next
Other Internet Services
E-mail
Transmission of Messages Over Internet
Messages May Include Attachments
Files, Graphics, Audio, Video
Virus
Volume
1.4 Billion Active Accounts Worldwide
183 Billion E-mails Sent Daily in 2006
World population?
History of the Internet
How did the Internet originate?
ARPANET
Goal:
To allow scientists
at different
locations to share
information
p. 68
Networking project by
Pentagon’s Advanced
Research Projects
Agency (ARPA)
Goal:
To function if
part of network
were disabled
Became
functional
____?_____
Next
Internet Development Milestones
 1969
Arpanet
 1980’s NSF connects
Internet
 1989
Tim Berners-Lee
 2003
Web2.0
Myths About the Internet
The Internet is Free
Someone Controls the Internet
The Internet and World Wide Web are One and the
Same
The Internet
Who controls the Internet?


No one — it is a public, cooperative, and
independent network
Several organizations set standards
c
c
World Wide Web
Consortium (W3C)
 Oversees research, sets
standards and guidelines
Click to view Web Link,
click Chapter 2, Click Web
Link
from left navigation,
then click W3C
below Chapter 2
p. 51
Next
History of the Internet
How has the Internet grown?
Today
More than 350 million host nodes
1984
More than 1,000 host nodes
1969
Four host nodes
p. 69
Next
Defining the World Wide Web
The WWW is a retrieval system which
organizes data into _____ _____ and the
pages are connected to each other via
__________. Multiple pages are called a
_____ _____. The computer that contains
the Web pages is a ______.
The World Wide Web
What are the twelve basic types of Web sites?
Portal
Advocacy
p. 61 – 63
News
Blog
Informational
Wiki
Business/
Educational Entertainment
Marketing
Network
Content
Aggregator
Personal
Next
How the Internet Works
How can you connect to the Internet?
Slow-speed
technology
Dial-up access
modem in your
computer uses a
standard telephone line
to connect to the Internet
Connection must be established
each time you log on.
Slow but inexpensive
p. 51 - 52
High-speed
connection
DSL, cable modem,
fixed wireless, Wi-Fi,
and satellite modems
Connection is always on—
whenever the computer
is running
Next
Internet Mechanics
Access Providers
ISP (Internet Service Provider)
OSP (Online Service Provider)
Member-only Features
AOL
MSN
Wireless
How to Connect
Internet Service Providers
Local ISP
http://www.mssinternet.com/
Earthlink – National ISP
Telephone Companies
AT&T
TV Service Providers
DirecTV
Colleges & Universities
Online Service Providers
AOL
MSN
Cybercafes
Copy Service Stores
Free ISP
http://home.pacbell.net/dbk4297/freeisp.ht
ml
Libraries
Employers
What are ways to access the Internet?
The World Wide Web
What is a Web browser?

Program that allows you to view Web pages
Microsoft
Internet
Explorer
Opera
p. 54
Firefox
Chrome
Safari
Netscape
Next
Google Chrome
Google Maps
Sally’s Recipes
YouTube
Blogger
Google search engine
iGoogle = individual
Gmail
http://www.google.com/chrome
The World Wide Web
How does a Web browser display a home page?
Step 2.
Web browser
looks up the
home page
setting
Step 3.
Step 1.
Click the Web browser
program name
Step 4.
The home page
displays in the Web
browser
p. 55 Fig. 2-5
The Web browser
communicates with
the access provider’s
server to retrieve the
IP address. The IP
address is sent to
your computer.
Next
Hyper Text Transfer Protocol –
HTTP – Web 1.0
The World Wide Web
How can you recognize links?



Pointer changes to a small hand
when you point to
a link
A link can be text
or an image
Text links are
usually underlined
and in a different
color
p. 57 Fig. 2-7
Next
The World Wide Web
What is a URL?
Unique address for a
Web page
 A web server delivers
the Web page to your
computer
p. 56 Fig. 2-6
Next
World Wide Web
Web Addressing
URL (Uniform Resource Locator)
Unique Address for Page Located on Web Server
protocol
path
domain name
http://www.nationalgeographic.com/travel/index.html
How the Internet Works
What is a domain name?

Text version of Internet protocol (IP) address
 Number that
uniquely identifies
each computer or
device
connected to
 Internet
p. 53 - 54 Figs. 2-3 – 2-4
Next
Internet Protocols
Gopher is a retrieval system at
the University of
__________which provides a
hierarchical menu system.
FTP sites allow users to retrieve
data and programs to their
own computer.
Telnet
allows users
to connect to a host
and perform
operations.
Other Internet Protocols
What is FTP?
File Transfer Protocol

Next
Internet
standard
that allows
you to
upload and
download
files with
other
computers
on Internet
p. 2.33 Fig. 2-29
file
downlo
dialog
box
Subdomain
http://teach.webcms.net
How the Internet Works
What is a domain name?

Text version of Internet protocol (IP) address

p. 74 Figs. 2-4 – 2-5
Number that uniquely identifies
each computer or device
connected to Internet
Evolution of the Internet
Other Internet Services
What is an e-mail address?

Name that consists of a user name and domain name
that identifies the user
p. 70 Fig. 2-19
Next
Other Internet Services
What is an e-mail address?
Combination of user name and domain name that
identifies user so he or she can receive e-mail
User name or user-ID
A unique combination of
characters that identifies you
at
Domain name
Identifies the mail server
Kburke@cdnet.cod.edu
Next
p. 2.31 Fig. 2-27
URL:
http://www.nationalgeographic.com/travel/index.html
E-Mail:
Kburke@cdnet.cod.edu
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 service
provider’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.
p. 70 Fig. 2-20
Software on outgoing mail server
determines best route for data and sends
message, which travels along Internet
routers to recipient’s incoming mail server
Next
The World Wide Web
A plug-in is a program that extends the capability of a
Web browser
The World Wide Web

Two types of search tools are search engines and
subject directories
Search
engine
Finds
information
related to a
specific topic
Subject
directory
Classifies Web
pages in an
organized set of
categories
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
p. 80 Fig. 2-12
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
Spider / Crawler / Bot
p. 57 - 60 Fig. 2-8
Netiquette = Code of acceptable Internet behavior
The World Wide Web
What is a home page?


The first page that a Web site presents
Often provides connections to other Web pages
p. 76 Fig.2-1a
Next
The World Wide Web
What is a portal?

A Web site that offers a variety of services from one,
convenient location, usually for free

p. 82 Fig. 2-13a
Searching, sports, e-mail,
news, weather, auctions,
Web communities
(Web sites that join
people with similar
interests)
Next
The World Wide Web
What is downloading?



p. 76
The process of a computer receiving information
Depending upon connection speed, downloading can
take from a few seconds to several minutes
Public domain vs. Shareware
Next
The World Wide Web
What graphics formats are used on the Web?
BMP
JPEG
PNG
(pronounced JAY-peg)
(pronounced ping)
GIF
(pronounced JIFF)
TIFF
Graphic format comparisons
p. 84 Fig. 2-16
Next
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 compression
standard
p. 88 Fig. 2-20
Next
Other Internet Services
What are newsgroups and message boards?

Newsgroup


Online area where users discuss a particular subject
Message board


Type of discussion group
Many Web sites use
message boards
because they are
easier to use
Click to view Web Link,
click Chapter 2, Click Web Link
from left navigation,
then click Newsgroups and
Message Boards
below Chapter 2
p. 95 Fig. 2-28
Next
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
Click to view Web Link,
click Chapter 2, Click Web Link
from left navigation,
then click Mailing Lists
below Chapter 2
p. 97 Fig. 2-29
Next
What is Web2.0 ?

Interactive rather than static

Uses “cloud” computing

Separates form from content
– Web 1.0 used html
» Programmer creates content
– Web 2.0 uses XML
» User creates content
» Collaboration
Web 2.0 Applications

Listed at:
•

http://www.go2web20.net/
Example
•
http://www.polleverywhere.com
Web 1.0
Web 2.0
Double-click
Adsense
Kodak Express
Flickr
Web 2.0
Web 2.0 Defined
The Machine is Using Us
Social Networking
Social Networking without Partying
List of Social Networking Website
Criticism of Web 2.0
Why some consider Web2.0 another bust