Uta005 lecture1

The Internet and World Wide Web

What You Will Learn About
The Internet and its history
The differences between the Internet and the Web
The concept of hypertext
Web browsers and Web servers
The parts of a URL

What You Will Learn About
The elements of Internet addresses
The most popular Internet services
Web subject guides and search engines
Search operators
The reliability of information on a Web page

The Internet
 The Internet is a global, interconnected computerThe Internet is a global, interconnected computer
network in which every computer connected to it cannetwork in which every computer connected to it can
exchange data with any other connected computer.exchange data with any other connected computer.

The Significance of the Internet
 It’s the first mass medium that involves computersIt’s the first mass medium that involves computers
and uses digitized data.and uses digitized data.
 It provides the potential for media convergence, theIt provides the potential for media convergence, the
unification of all media.unification of all media.
 It’s transforming how we communicate, obtainIt’s transforming how we communicate, obtain
information, learn, seek jobs, and maintaininformation, learn, seek jobs, and maintain
professional growth.professional growth.
 Businesses find it an indispensable tool for theirBusinesses find it an indispensable tool for their
needs.needs.

The Internet’s History
Significant events in the history of the Internet.
1962
1969
1972
1983
1989 1994
1995
J.C.R.
Lickliter
conceives
of the idea
of a
“galactic
network”.
Ray Tomlinson
invents e-mail.
The World Wide
Web is
developed.
The first
graphical
Web
browser is
developed.
ARPANET goes
online, connecting
four computers.
Internet
protocols
begin.
Barriers to
commercial
activity are lifted.
Click on the dates for more information.

The Internet and Web: What’s the Difference?
The Internet is the physical connection of millions of
networks.
The Web uses the Internet for its existence.
The Web consists of hypertext embedded on Web
pages that are hosted on Web sites.

The Web Site
A Web site is a collection of
related Web documents that
are made available to the
public.
The index page, or home
page, is the first page of a
Web site.
Web pages are individual
Web documents.

The Hypertext Concept
Hypertext is a way of presenting information so that
the order in which it’s read is left up to the reader.
Hyperlinks are underlined or highlighted words that
can be used to view another document or Web page.
Hypermedia refers to a link to multimedia, such as
music and movies.
The Web is a distributed hypermedia system or a
system where the responsibility for creating content
is distributed among many people.

Web Browsers and Servers
Web browsers display a Web document and enable
users to link to other Web pages.
The first browsers were text-only.
Mosaic was the first graphical browser.
Web servers respond to the requests of browsers.
They find and send requested resources back to the
browser.

© 2005 Prentice-Hall, Inc Slide 11
 Web addresses are an addressing system that identifies
where a Web resource is located.
 The uniform resource locator (URL) is the standard
used to identify Web resources.
 The URL consists of:
URL
Web Addresses (URLs)
http://
Protocol
identifies
the means
of access
www.yahoo.com/
Server contains
the domain
name of the
Web server
help/shop/
Path
identifies the
location of the
document
shop-01.html
Resource
specifies the
filename of the
resource

Browsing the Web
To access a Web page, you can do any of the
following:
Click a hyperlink.
Type a URL in the Address box.
Click a button on the Links toolbar.
Use the Back and Forward buttons.
Use a Web site’s navigation aids.
Use the History list.
Use the Favorites or Bookmarks list.

Standard Toolbar–
Contains Navigation buttons
Address Bar–
Contains URL of
Web page
Back & Forward Buttons–
Take you to recently visited
pages
Stop Button–
Stops downloading
Refresh Button–
Updates (refreshes) the
page
Home Button– Returns
to default start page
Search Button– Opens
search engine program
Favorites Button– List of
bookmarked Web pages
Media Button– Opens
media player program
History Button– List of
Web sites visited over a
period of time
E-Mail Button– Opens
e-mail program
Printer Button– Prints
documents
Other Navigation ButtonsProgram icon–
Animates when
downloading
Status bar– Messages
about the browser’s
operation
Hyperlinks
The Web Browser’s Window
Click to view the various parts of a Web browser’s window.

HTML
Document
Web Page Design
Authors use a markup language called Hypertext
Markup Language (HTML) to create Web pages.
The markup language consists of codes that identify
portions and special effects in the document.

Page CreatedHTML Document
Click to view an HTML document and the page that it creates.
Click again

How the Internet Works
The Internet provides immediate and direct contact
with all computers on the network.
All Internet computers have an Internet address (IP
address).
Internet service providers (ISPs) sell subscriptions to the
public.
Its interoperability feature enables access for all types of
computers.
Large organizations maintain the Internet.
Many private and public networks are linked together to
provide a worldwide networking system.
Packet switching technology is used to transmit data.

Internet Protocols
Transmission control protocol (TCP) – A standard
that defines how one computer can communicate and
exchange data with another computer on the Internet.
Internet protocol (IP) – Defines the Internet’s
addressing scheme.
IP address – Each computer connected to the
Internet is given an address composed of numbers
and periods. Example: 209.234.456.8

Domain Name
Domain Names
 Domain Name System (DNS) – Enables users to type names of
Web sites and Web pages as well as IP addresses. Example:
www.thapar.edu or 112.23.345.56
 Domain name registration – Enables individuals, businesses,
and organizations to register their Web sites with InterNIC.
 The last part of the domain name gives the type of organization
that maintains the site. Examples: .com, .net, .edu, and .gov.

Accessing the Internet and Web
You will need:
 A computer with an operating system, such as Windows,
MAC OS, or UNIX, that supports Internet protocols
 Communications equipment such as a modem, ISDN
adapter, or Ethernet card
 An Internet service provider (ISP)
 Web browser software such as Internet Explorer or Netscape
Navigator

Accessing the Internet
 The Internet can be accessed in the following ways:
Dial-up access with Point-to-Point Protocol (PPP)
Digital Subscriber Line (DSL)
Cable and satellite access
LAN access

R
E
G
I
O
N
A
L
L
O
C
A
L
1. You request a
Web page.
2. Your request
goes to your
ISP’s point of
presence (POP).
3. Your request
goes to a
network access
point (NAP).
4. Your request
goes to a national
backbone network.
5. Your request
reaches the Web site’s
server and the Web
page is sent back to
you in packets.
YOU ARE
HERE
NATIONAL
Click to view
animation. Click
once only.
ISPs and Backbone Service Providers

Intranets and Extranets
 Intranet – An internal
networking system within a
company
 They function like the
Internet
 They are for internal use only
and are not available to those
outside the company
 Firewall – Software used to
screen incoming data
 Extranet – An intranet that
can be used by outside sources
who access it over the Internet

The Internet vs. Online Services
 An online service is proprietary. It provides services through
its network. Some examples of services provided: e-mail, chat
rooms, customized content, and Internet access.
 Web services provide a portal (gateway) to connect to the
Internet without offering many other services.
Online Service Web Service

E-Mail: Staying in Touch
 E-mail is short for electronic mail.
 It’s the most popular of the Internet services.
 Messages are sent and received in a few seconds.
 Attachments such as photos, music files, and any
document may be sent with the message.

Instant Messaging: E-Mailing Made Faster
 Instant messaging systems let a user know when a friend or
business associate is online.
 It provides a means of communicating through real-time,
text-based conversations.

IRC: Text Chatting in Real Time
 Internet relay chat consists of real-time, text-based
conversations.
 Chat groups are divided into channels that cover a
specific topic.

Your Computer FTP Server
DOWNLOAD
UPLOAD
File Transfer Protocol (FTP)
 FTP is a part of the Internet that enables client computers to
transfer files.
 Transferring files from an FTP site to the client is known as
downloading.
 Transferring files from the client to an FTP site is known as
uploading.
 Clients may store files on an FTP site’s server.

Usenet
 Usenet is the part of the
Internet which enables users
to participate in discussions
and newsgroups.
 Usenet newsgroups are
organized into hierarchies
(categories) and
subcategories.
 Subcategories include
Standard, Alt, Biz, and Local
newsgroups.

Listservs: Electronic Mail Lists
A listserv is an automatic
list server.
Mail is sent to everyone
on the list when e-mail is
generated.
It is similar to a
newsgroup or a forum.

Internet Telephony
Internet telephony
consists of real-time
voice and video
conversations.
A microphone, sound
card, and digital video
camera are required for
videoconferencing.

Finding Information on the Web
Ways to find information on
the Web:
Browse or surf the Web – This
involves linking from one Web
page to another, and so forth.
Search the Web – This method
involves using search engines to
locate Web pages with the
information you’re looking for.
Subject guides – Web pages are
grouped under headings.

Using Search Engines
 To use a search engine, you:
 Choose a search engine (MSN, Lycos, Alta-Vista, Yahoo,
etc).
 Type in one or more words describing your topic.
 The search engine checks its database of Web pages
that contain the words typed.
 The results are sent to your computer.
 Clicking on the link takes you to that page.

Using Search Techniques
Learning a few search techniques can increase the
accuracy of Web searches.
Searches using search operators will improve search
performance.
Most search engines use the following search
operators:
Inclusion/exclusion operators
Wild cards
Phrases
Boolean operators

 The following tables show the results of using and not using
search operators.
Words
Entered
Possible Results –
Web pages
containing
Fire station
Fire
station
Fire station
Words Entered Possible Results –
Web pages containing
+Fire+station Fire station
+Fire+station* Fire station
Fire stations
+Fire-station* Fire
“Fire station” Fire station
Fire and station Fire station
Fire or station
Fire
station
Fire station
Fire not station Fire
No Search Operators
Using Search Operators
Using Search Techniques

Rules for Evaluating Web Pages
1. Author – Who is the author?
2. Sources – Where does the information come from?
3. Server – Who provides the server for the page?
4. Objectivity – Is the information objective or one-
sided?
5. Style – Is the language objective or argumentative?
6. Purpose – What is the purpose of the page?
7. Accuracy – Is the information accurate?
8. Currency – Is the page up-to-date?

Summary
• The Internet is a global network providing direct access to
computers worldwide.
• Because of its cross-platform feature, computers of all types can
use the Internet.
• Related information, in hypertext documents, is referenced by
linking to other documents.
• The user’s Web browser is known as the client, and the Web
server retrieves documents requested by the client.
• A URL consists of the:
Protocol
Server
Path
Resource name
• Web pages are created using Hypertext Markup Language
(HTML).

Summary (continued)
• Online services are proprietary.
• Client software enables information to be accessed, and server
software delivers the information.
• An Internet address uniquely identifies each computer
connected to the Internet.
• Intranets enable companies to set up internal communications.
• Popular Internet services include:
E-mail
World Wide Web
FTP
Usenet
Listservs
Instant messaging
Internet Relay Chat
Internet telephony

Summary (continued)
• You can improve search results by using inclusion operators,
phrases, and Boolean operators.
• Critically evaluate the author’s credentials and purposes for
publishing when reading Web pages.

Uta005 lecture1

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Uta005 lecture1