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Discovering Computers 2008
Chapter 2The 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?
p. 68 Fig. 2-1 Next
4. Chat
(4)
(1)
1. E-mail
(2)
2. Web
(3)
3. File transfer
(5)
5. Message board
(6)
6. Instant messaging
Other Internet Services
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?
Nextp. 68
Goal:To function if
part of network were disabled
Became functional ____?
_____
ARPANET
Networking project by Pentagon’s Advanced
Research Projects Agency (ARPA)Goal:
To allow scientists at different
locations to share information
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?
p. 51
World Wide Web Consortium (W3C)
Oversees research, sets standards and guidelines
Next
No onec—cit is a public, cooperative, andindependent network
Several organizations set standards
Click to view Web Link,click Chapter 2, Click Web Linkfrom left navigation, then click W3Cbelow Chapter 2
History of the Internet
How has the Internet grown?
p. 69
TodayMore than 350 million host nodes
1984More than 1,000 host nodes
1969Four host nodes
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 ______.
Advocacy Blog WikiNetwork
ContentAggregator Personal
Portal
The World Wide Web
What are the twelve basic types of Web sites?
p. 61 – 63 Next
News InformationalBusiness/Marketing
Educational Entertainment
High-speed connection
High-speed connection
Slow-speed technology
Slow-speed technology
How the Internet Works
How can you connect to the Internet?
p. 51 - 52 Next
Dial-up accessmodem in your computer uses a
standard telephone line to connect to the Internet
Dial-up accessmodem in your computer uses a
standard telephone line to connect to the Internet
DSL, cable modem,fixed wireless, Wi-Fi,
and satellite modems
DSL, cable modem,fixed wireless, Wi-Fi,
and satellite modems
Connection is always on—whenever the computer
is running
Connection is always on—whenever the computer
is running
Connection must be established each time you log on. Slow but inexpensive
Connection must be established each time you log on. Slow but inexpensive
Internet Mechanics
Access Providers
ISP (Internet Service Provider)
OSP (Online Service Provider)
Member-only Features
AOL
MSN
Wireless
How to Connect
Internet Service ProvidersLocal ISPhttp://www.mssinternet.com/
Earthlink – National ISP
Telephone CompaniesAT&T
TV Service ProvidersDirecTV
Colleges & Universities
Libraries
Employers
Online Service ProvidersAOLMSN
Cybercafes
Copy Service Stores
Free ISP
http://home.pacbell.net/dbk4297/freeisp.html
What are ways to access the Internet?
The World Wide Web
What is a Web browser?
p. 54 Next
Program that allows you to view Web pages
MicrosoftInternetExplorer
Firefox
Opera
Chrome
Safari
Netscape
Google Maps
Sally’s Recipes
YouTube
Blogger
Google search engine
iGoogle = individual
Gmail
Google Chrome
http://www.google.com/chrome
The World Wide Web
How does a Web browser display a home page?
p. 55 Fig. 2-5 Next
Step 3.The Web browser communicates with the access provider’s server to retrieve the IP address. The IP address is sent to your computer.
Step 1.Click the Web browser program name
Step 2.Web browser looks up the home page setting
Step 4.The home page displays in the Web browser
Hyper Text Transfer Protocol – HTTP – Web 1.0
hyperli
nks
HTML
Script
Language
The World Wide Web
How can you recognize links?
p. 57 Fig. 2-7 Next
A link can be text or an image
Pointer changes to a small handwhen you point toa link
Text links areusually underlinedand in a differentcolor
The World Wide Web
What is a URL?
p. 56 Fig. 2-6 Next
Unique address for a Web page
A web server delivers the Web page to
your computer
World Wide Web
Web Addressing
URL (Uniform Resource Locator)
Unique Address for Page Located on Web Server
protocoldomain name
path
http://www.nationalgeographic.com/travel/index.html
How the Internet Works
What is a domain name?
p. 53 - 54 Figs. 2-3 – 2-4 Next
Text version of Internet protocol (IP) address
Number that uniquely identifies each computer or device connected to
Internet
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
file download dialog box
What is FTP?
File Transfer Protocol
Internet standard that allows you to upload and download files with other computers on Internet
p. 2.33 Fig. 2-29
Next
Subdomain
http://teach.webcms.net
How the Internet Works
What is a domain name?
p. 74 Figs. 2-4 – 2-5
Text version of Internet protocol (IP) address Number that uniquely identifies
each computer or device connected to Internet
Evolution of the Internet
Other Internet Services
What is an e-mail address?
p. 70 Fig. 2-19 Next
Name that consists of a user name and domain name that identifies the user
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
p. 2.31 Fig. 2-27
Next
Other Internet Services
How does an e-mail message travel?
p. 70 Fig. 2-20 Next
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 2.Your software contacts software on your service provider’s outgoing mail server
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
Step 1.Using e-mail software, you create and send
message
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
The World Wide Web
What is a subject directory?
p. 80 Fig. 2-12
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 is a search engine?
p. 57 - 60 Fig. 2-8
Program used to find Web sites and Web pages by entering words or phrases called search text
Spider / Crawler / Bot
Netiquette = Code of acceptable Internet behavior
The World Wide Web
What is a home page?
p. 76 Fig.2-1a Next
The first page that a Web site presents Often provides connections to other Web pages
The World Wide Web
What is a portal?
p. 82 Fig. 2-13a Next
A Web site that offers a variety of services from one, convenient location, usually for free Searching, sports, e-mail,
news, weather, auctions, Web communities (Web sites that join people with similar interests)
The World Wide Web
What is downloading?
p. 76 Next
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
The World Wide Web
What graphics formats are used on the Web?
p. 84 Fig. 2-16 Next
BMPBMP
GIF(pronounced JIFF)
GIF(pronounced JIFF)
JPEG(pronounced JAY-peg)
JPEG(pronounced JAY-peg)
PNG(pronounced ping)
PNG(pronounced ping)
TIFFTIFF
Graphic format comparisons
The World Wide Web
What is video?
p. 88 Fig. 2-20 Next
Consists of full-motion images with soundplayed back at various speeds
MPEG (Moving Pictures Experts Group) is popular video compressionstandard
Other Internet Services
What are newsgroups and message boards?
p. 95 Fig. 2-28 Next
Newsgroup
Click to view Web Link,click Chapter 2, Click Web Linkfrom left navigation, then click Newsgroups and Message Boards below Chapter 2
Many Web sites use message boards because they are easier to use
Online area where users discuss a particular subject Message board
Type of discussion group
Other Internet Services
What is a mailing list?
p. 97 Fig. 2-29 Next
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 Linkfrom left navigation, then click Mailing Lists below Chapter 2
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
