Transcript Chapter 8 PowerPoint Slides - UB Computer Science and Engineering

Chapter 8:
The Internet and the Web:
World Wide Transformation
The Internet grew from a grass-roots society into a
global community. Keeping this in mind, whose
rules will we need to follow when we make use of
the World Wide Web?
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The Internet and the Web:
World Wide Transformation

In this chapter:
• How has the Internet and the WWW been used as a tool of
influence and persuasion?
• How did the Internet evolve into what it is today?
• What are some popular services, past and present?
• Who owns the Web?
• How can you access the Internet from home?
• What can be downloaded for free, and what for a fee?
• How are web pages created?
• What kinds of search services are out there?
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A Powerful Voice

The Internet and Web continue to emerge as powerful
tools of influence and persuasion.
• After the 1989 Tiananmen Square massacre, Chinese students
in the U.S. used email as a vehicle to lobby for support from
Congress for protective legislation.
• Fall of 1993 - Russian President Boris Yeltsin suspended
parliament. Three Russian labor leaders were arrested. Vassily
Balog, the deputy head of Russia’s major labor confederation
began an email campaign. After phone calls came in from
around the world, the three were released.
• During the U.S. Primaries from 1999-2000, John S. McCain
raised over $750,000 because of a letter he posted on his
campaign’s WWW home site.
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The Internet:
Struggling to Maturity
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Early 1960’s
• Packet-switching envisioned (Baran and Davies)
• Provided the foundation for what became the Internet.

1966: ARPAnet (Advanced Research Projects Agency
NETwork)
• Funded by ARPA (Advanced Research Projects Agency).
• Pooled computer scientists and resources from several
universities.
• In 1969, linked 4 nodes at UCLA, UC Santa Barbara, SRI
(Stanford Research Institute) and U of Utah.
• By mid-1970’s, linked several military sites and about 20
universities.
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The Internet:
Struggling to Maturity

ARPA intended to sell off the ARPAnet to an academic
or corporate consortium.
• Before the sale, federal rules required the Defense Department
to determine if ARPAnet was needed for national defense.
• ARPAnet was transferred to the Defense Communications
Agency in 1975.
• Only about 15 universities were given access to the network.
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1980: National Science Foundation started CSnet
• Purpose: To provide a resource-sharing network opportunity
to computer science research at all universities.
• Used TCP/IP protocol.
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The Internet:
Struggling to Maturity

CSnet fueled interest in creating a more comprehensive
network to link all scientific communities (not just CS)
• NSF couldn’t fund such an expensive project.
– Backbone: NSF built a very fast connection between 5
supercomputing centers linking them all together.
– Each region surrounding each center would develop its
own community network.
– NSF allowed the regional community networks exclusive
use of the backbone.
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The Internet:
Struggling to Maturity
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1983: ARPAnet split.
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Converted from Network protocol to TCP/IP protocol.
Part remained ARPAnet: universities, research institutes.
Part became Milnet: non-classified military information.
By 1989, ARPAnet was costing $14 million per year to keep
up and running.
1989: majority of ARPAnet switched to NSF’s
backbone.
• ARPAnet sites were connected to the NSF backbone through
the regional community networks.
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
NSFnet became what is known as the Internet.
Early 1995: “Information Superhighway.”
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Internet Services

Four examples of popular Internet functions illustrate
the diversity of Internet use:
• University sites provide class and faculty information, books,
and periodicals from the library, and lists of governmental
documents.
• Employment offices provide vacancy notices and job
descriptions.
• Various governmental agencies provide informational
documents. (jobs, how-to documents, forms)
• Students and academic researchers could find bibliographies.
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Internet Services

Internet owes its critical mass to the wide distribution
of computers running the UNIX operating system.
• Original access to the Internet had a UNIX “feel.”
• Exact addresses were needed to access information.
– Addresses were given as strings of numbers.
– Address for UCSD: 128.54.16.1
• In the early days of the Internet, people who could navigate
the Internet were considered specialists and were well paid for
the use of their skills.
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Internet Services

Internet needed improvements in user-friendliness.
Three early creations satisfied the need:
• Gopher
• Veronica
• Archie
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Gopher (University of Minnesota):
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Land of the “Golden gophers.”
Introduced first improvement to accessing the Internet.
Menu-driven system gave access to databases of information.
Were once over 5,000 gopher servers.
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Internet Services
Internet Gopher Information Client v2.1.3
Home Gopher server: gopher.tc.umn.edu
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
Information About Gopher/
Computer Information/
Discussion Groups/
Fun & Games/
Internet file server (ftp) sites/
Libraries/
News/
Other Gopher and Information Servers/
Phone books/
Search Gopher Titles at the University of Minnesota <?>
Search lots of places at the university of Minnesota <?>
University of Minnesota Campus Information/
Press ? For Help, q to Quit, u to go up a menu
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Internet Services

Searching for information on the Internet from Gopher:
• Veronica:
– Very Easy Rodent-Oriented Netwide Index to Computerized
Archives.
– Finds only sites related specifically to the topic of interest.
– Updated about twice weekly.
• Archie: One of the oldest search systems
– Original purpose: Used to find data files on the Internet.
– Designed to search ftp archive sites.
– FTP files could then be downloaded using the Internet FTP
program.
– Expanded to include resource listings and online directories.
– Currently accessible through the WWW.
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Using the Internet

Email (Electronic mail)
• The most prevalent use of network applications.
• Not as private as regular mail.
– Partially because it hasn’t been around long enough to
develop privacy laws or security systems.
– Computers make it easy to copy and snoop into
unprotected files.
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Using the Internet

Bulletin Board System (BBS)
• Provides a messenger service.
• Used as a repository for software and documents that may be
copied.
• Provides a place for people to converse.
• This type system is quickly being replaced by the World Wide
Web.
– BBS’s are still in existence.
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Using the Internet

Conferences Online
• Computer conference (electronic conference): An electronic
meeting that can take place at the convenience of the
participants.
– Conference participants can type in questions or
comments so that other members can see them and
respond.
• WELL (Whole Earth ‘Lectronic Link)
» Has thousands of users accessing more than 100
public conferences (topics).
• Usenet (Users’ Network)
» Hundreds of conferences organized by topic.
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Using the Internet

IRC (Internet Relay Chat)
• Developed in 1988 by Jarkko Oikarinen in Finland.
– The original was a text-based Internet version.
• “Real-time” online chat facilities: chat rooms.
• Communication is accomplished via typing text over a
“channel”
– Participants can occupy one of the many public chat
rooms where everyone can read and respond, or go into
“private rooms” or “celebrity” chat rooms.
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And Then Came the Web
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World Wide Web (WWW or the Web)
• A computer communications system that allows multimedia
information to be accessed and transmitted via the Internet.
– Multimedia: Producing different types of information
(text, sound, graphics, and/or video) simultaneously.
• The Web follows the Hypertext Transfer Protocol.
– 1989: Tim Berners-Lee created the HTTP.
– HTTP: A set of rules implemented in a program.
– Allows an individual computer to participate with other
computers through the Internet.
– Converts text, visual and audio information into packets to
traverse the Internet.
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And Then Came the Web
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Who owns the Web?
• No one owns the web.
• Access is the key issue on the Web.
– The Web is made up of a network of computers and other
networks.
– Each entry point to the Web is controlled by an organization that
provides the service. They “own their own piece” of the Web.
– Mutually accepted protocols, TCP/IP and HTTP, are used by all
who access the WWW.
– Organizations allow read-only access to certain files and
documents on their computer’s storage device. (These are the
pages one sees and the files that can be retrieved.)
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Navigating the Web

The World Wide Web uses point and click navigation
accomplished by the use of:
• Hypertext - Refers to any word or phrase in an electronic
document, which can be used as a pointer to a related text
passage.
• Hypertext link - Any text or image that has been designated
as a means of accessing related material.
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Navigating the Web

Columbus sailed west
under the auspices of
Queen Isabella of Spain.
She commissioned...
In hypertext, one
follows the links to
related information.
Queen Isabella’s
husband was King
Ferdinand...
A biography of
King Ferdinand,
he reigned from...
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Navigating the Web

When setting up links, the creator of a Web page
would follow these steps:
• Identify the specific words that will be useful as links.
• Search for and locate the related text or additional information
the hypertext will access. (Could be another web page.)
• Set pointers containing information on how to find the
document containing the related information.
• Have the selected words printed in a special color and
underlined so that the reader can recognize them as hypertext.
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Navigating the Web

Hypermedia: Hypertext linking with other communications
mediums, such as pictures, animations, and sound.
• Hypermedia links are often called hyperlinks.
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Understanding Web
Addresses (URLs)

Surfing the Web
• The slang term used to
describe the free-form
navigation from place to
place on the Internet by
following hyperlinks.
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Understanding Web
Addresses (URLs)
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A Web Page
• A document especially created for Web viewing.
• Contains at least some of the following: text, images,
graphics, sound, animation, hyperlinks.
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Links:
• Appear in Web pages.
• Clicking on a link may send you to another Web page.
• Links need two types of information:
– The instruction to locate and display the second page.
– The location, or address, of where to find it.
• Technical name: Uniform Resource Locator (URL)
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Understanding Web
Addresses (URLs)

A Uniform Resource Locator (URL) has 3 parts:
1) Type of connection (specifies protocol used at that location):
Name
HTTP
FTP
SMTP
FILE
Gopher
WAIS
Telnet
Definition
HyperText Transport
Protocol
File Transfer Protocol
Email Protocol
Local file access
Name of Internet
access system
Wide area info. Service
Telephone Networking
Description
Mode through which WWW uses the Internet.
Used for transferring files between computers.
Used to send/create an email link.
Used to view HTML files.
Transfer type used by Gopher systems.
Tool for searching information databases.
Service for logging on to remote computers.
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Understanding Web
Addresses (URLs)
2) The Internet address (domain name) of the computer you are trying
to access: (Locates the specific computer on the Internet.)
1 Type of connection
Top-level Domain
3a Path or Directory
http://www.eds.com/home/eds_home.html
2 Domain
Domain name: Identifies the
Internet address
Sub-domains: Includes the
Server name and Top-level
Domain which identifies the
type of organization.
3b File name
com
edu
gov
mil
net
org
Commercial site
Educational Institution
Government organization
Military organization
Networking organization
Nonprofit organization
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Understanding Web
Addresses (URLs)
3) The path and name of the file:
• Identifies the location of the file and the name of the file to be
displayed on your screen.
• If the path (folder or subdirectory) or name of file have been
changed:
– An error message will appear on your screen!
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The Web and You

Accessing the Web (What you need to get connected!)
• A computer:
– The faster and the bigger, the better.
– Minimal setup recommended: 300 MHz, 64 MB RAM, 2
GB hard disk space.
• A modem:
– Minimal setup: 28.8 Kbps; 56 Kbps will enhance
performance.
• An Internet Service Provider: Your dial-up entry point to the
web.
– Usually charge a fee to access their system.
– They have servers linked to the Internet.
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The Web and You

Web browser:
• A program that allows you to access all of the multimedia
components of Web pages. (support HTTP protocol)
• Two major products: Netscape Navigator and Microsoft
Internet Explorer.
• With Web Browsers, you can:
– “Read” the contents of Web documents.
– Print out a paper copy of the Web document.
– Copy text into a word processing document.
– Save and use pictures and animations.
– Read email, Chat with others, Transfer files.
– Keep an address book of favorite sites.
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The Web and You
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Downloading software:
• The process of receiving a program, document, or file via a
network, from another computer.
• Always comes electronically from an outside source to your
computer.
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The Web and You
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Free Downloads
• Search the WWW for the free file you want.
• Click on the name of the file to be downloaded.
– May require the use of FTP (File Transfer Protocol
software).
– Provided with most browsers and is done “invisibly.”
• Wait until the file is downloaded.
• You may need to “de-compress” the file.
– Run WinZip on Windows, StuffIt Expander on Macintosh
• Read the “Readme” file.
• Read the limitations of use on the license.
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The Web and You
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Shareware:
• Not all software found on the Internet is free, some request
that a fee be paid if the software is used.
• Sometimes, the fee includes:
– Documentation
– Phone support
– Notice of software updates
• Shareware comes with no guarantee of quality.
• Many viruses have been spread by shareware.
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The Web and You

Creating a Web presence:
• Web pages are normally created in any word processing
program using a special formatting language called HTML
(Hypertext Markup Language).
– HTML: A series of codes, or tags, which are used to
format materials used on Web pages.
• Once the coded version of the page is uploaded (sent to) the
Internet Service Provider’s computer, it can be viewed by
anyone with a browser and the address of your page.
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The Web in Business:
The Growth of E-Commerce
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Potential benefits of having a “Web presence” for a
business: an accessible, online place to do business.
• Original main purpose: To give the company an electronic
presence.
• Electronic Commerce is sweeping the country: Made up of
online advertising, buying, and selling of goods and services.
• Three main drivers behind the power of E-commerce:
1. Lower transaction costs for both business and client.
2. Larger purchases per transaction and more
transactions per client.
3. Integration of Internet activities into the business
cycle: from the time it is ordered, to the time it
reaches the consumer’s hands.
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The Web in Business:
The Growth of E-Commerce
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E-commerce encourages potential customers to visit
their sites and return to buy additional items.
• Web sites must be easy to find.
– Many companies include links on some of the more
popular web sites.
• Web services like Excite and Yahoo sell add space.
• Adds take the form of an icon, banner, or border.
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The Web in Business:
The Growth of E-Commerce
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Paying for E-commerce Purchases
• Credit card:
– Fears: Victim of electronic theft.
– Losses: Credit card companies cover losses after the first
fifty dollars.
– Credit rating: Although the loss is covered, delaying the
payment may result as a bad debt.
– Secure channels: Prevent electronic theft.
• Charging to another account: Charging to your telephone bill.
• Electronic wallet: Allows prepayment to a service company.
• E-money: eCash™ service uses a special encrypted scheme
that does not allow the seller to trace where an electronic
payment originated.
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The Web in Business:
The Growth of E-Commerce
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Privacy and Consumer Profiling
• Consumer profiling: The business practice of collecting
consumer information from online-based activities and using
that information to create targeted marketing efforts.
• E-commerce business can collect very extensive information
about their customers in attempt to closely define consumer
needs and desires.
– Poll conducted in February 2000 of online customers:
• 93% - Profiling is a potential threat to privacy.
• 80% - Would like to specify how information about
them is to be used.
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Search Engines
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Searching the Web:
• Problem: How to find specific information from the
seemingly random mass of pages on the Internet?
• Search Engine: A program available through WWW
browsers that enables the user to search the Internet for
information on specific topics.
– Free search services provided on the Web.
– Many exist including; Lycos, HotBot, Excite, Yahoo,
Webcrawler.
– Search engines search by subject, topic, keyword,
concepts, text analysis, image content.
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Search Engines

The underlying technology of the search engine: the
spider.
• Spider: A piece of Web software that constantly searches for
new Web pages and follows any links found on them.
– A spider searches from site to site, perpetually, looking for
its intended object.
– Spiders search for titles of new web pages.
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Search Engines
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To perform a search, you simply type a query:
• Query: A request specifying what information is to be sought
in a search operation.
• Most often made up of one or more keywords (Criteria
selected to identify and narrow the specific information
desired in a search.)
Refining a Web search query:
Use more than one word to make your query more specific.
Use quotation marks to match an exact phrase.
Use a plus sign to indicate that one or more specific words must be in
all items found.
Use a minus sign to indicate a word must not be in any items found.
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