3. INTERNET????
• It is the largest network in the
world that connects hundreds of
thousands of individual networks
all over the world.
• The popular term for the Internet
is the “information highway”.
• Rather than moving through
geographical space, it moves your
ideas and information through
cyberspace – the space of
electronic movement of ideas
and information.
4. • No one owns it
• It has no formal management
organization.
• As it was originally developed by the
Department of defense, this lack of
centralization made it less
vulnerable to wartime or terrorist
attacks.
• To access the Internet, an existing
network need to pay a small
registration fee and agree to certain
standards based on the TCP/IP
(Transmission Control
Protocol/Internet Protocol) .
• A global network connecting
millions of computers
5. What is Web?
• The Web (World Wide Web) consists
of information organized into Web
pages containing text and graphic
images.
• It contains hypertext links, or
highlighted keywords and images that
lead to related information.
• A collection of linked Web pages that
has a common theme or focus is called
a Web site.
• The main page that all of the pages on
a particular Web site are organized
around and link back to is called the
site’s home page.
6. • Body (BAN)
• Personal (PAN)
• Near-me (NAN)
• Storage (SAN)
• Local (LAN)
• Home (HAN)
• Campus (CAN)
• Metropolitan (MAN)
• Wide (WAN)
• Global (GAN)
• Interplanetary Internet
Types of internet:-
7. • J.C.R, Licklider of MIT – first
proposed a global network of
computers in 1962.
• Leonard Kleinrock of MIT & later
UCLA developed theory of packet
switching (basic internet
connections)
• Ray Tomlinson – e-mail
HISTORY OF INTERNET
8. The Internet exploded into the
public consciousness in the mid
1990s
Approximately the Internet grew
from 72 million in 2000 to 162
million in 2002
E-commerce is growing rapidly.
Tim Berners-Lee is arguably the
pivotal figure in the surging
popularity of the Internet
THE INTERNET AS
PHENOMENON
9. GETTING START
The Internet Service Provider and
the Browser
An internet user needs
• a computer
• a modem (dial-up, cable
or DSL)
• a network connection
• the related software
• an Internet Service
Provider (ISP)
• Browser
An ISP provides the server
computer and software to
connect to the Internet
10. • A browser is software used to
explore the Internet
• Microsoft Internet Explorer (IE)
• Others like Netscape, Opera
Google crome and Mozilla are
available.
11. Uniform Resource Locators
• The IP address and the domain name each
identify a particular computer on the Internet.
• However, they do not indicate where a Web
page’s HTML document resides on that
computer.
• To identify a Web pages exact location, Web
browsers rely on Uniform Resource Locator
(URL).
• URL is a four-part addressing scheme that
tells the Web browser:
What transfer protocol to use for transporting
the file
The domain name of the computer on which
the file resides
The pathname of the folder or directory on
the computer on which the file resides
The name of the file
12. Structure of a Uniform
Resource Locators
http://www.chicagosymphony.org/civicconcerts/index.htm
protocol
Domain name
pathname
filename
http => Hypertext Transfer Protocol
13. communicating by using links
– the clickable text or image that
transport a user to the desired
web site
Domain name
- the address of the site’s host
computer.
- “com” called top-level domain and
represents the purpose of
organization or entity.
“com” – commercial
“edu” – education
“gov” – government
“org” – organization
“net” - networking center
HTTP(Hypertext
Transfer Protocol)
14. Hypertext Markup Language
(HTML)
• HTML uses codes, or tags, to tell the
Web browser software how to
display the text contained in the
document.
• For example, a Web browser reading
the following line of text:
<B> A Review of the
Book<I>Wind Instruments of
the 18th Century</I></B>
• recognizes the <B> and </B> tags as
instructions to display the entire line
of text in bold and the <I> and </I>
tags as instructions to display the
text enclosed by those tags in italics.
• The standard used on the web is
Hypertext markup language (HTML).
15. Search Engine
• A search engine is software, usually located
at its own web site, that lets a user specify
search terms; the search engine then finds
sites that fit those terms
• A browser usually offers links to one or more
search engines, or a user can simply link to
the site of a favorite search engine
• Example :
a. Yahoo
b. Altavista
c. About
d. AllTheWeb
e. Google
f. Lycos
16. A selection of Internet Search Tools
Directories
About Human experts, called
guides compile
directories organized
around specific topics
Yahoo! Well-organized
categories let the user
switch from browsing to
searching in a certain
area; but finds only
keywords, not any word
on a site.
AlltheWeb Fast; supports a large
number of languages;
can limit result to specific
domains.
AltaVista Very fast; indexes every
word on every page of
every site; searches
Usenet too; excellent for
custom searches.
17. Google Result raked
by algorithm
based on
number of
links from
other pages.
HotBot Fast; unique
search options
let you restrict
searches; very
comprehensive;
excels at
finding current
news
Lycos Numerous
search options,
a
comprehensive
directory, and
good returns on
simple
searches.
18. NON-WEB SERVICES OF
THE INTERNET
1. Newsgroups
2. File Transfer Protocol (FTP)
3. Telnet
4. E-mail
19. 1. Newsgroups
• Usenet – an informal network of
computers
Allows posting and reading of
messages
Typically focuses on specific topics
Requires a newsreader
• Some are moderated
– Messages sent to a moderator, who
determines whether the message is
appropriate
– Prevents users from attacking other
members and prevents
inappropriate material from being
posted
20. 2. File Transfer Protocol
(FTP)
• A protocol for transferring files
among computers.
• FTP servers maintain collections of
downloadable files
–Downloading can often be done
anonymously, without logging in
• Many FTP servers can be accessed
through Web browser
21. 3. Telnet
• A protocol that allows remote users to
log onto a host computer.
Users use their own PCs
Users log in over the Internet
Users’ experience is the same
as if they were sitting at the
host computer’s local terminal
• Remote user typically has to have
a user ID and password
22. 4. E-mail
• The most commonly used feature of the
Internet
• Network provides mail server :
– Collects and stores messages in mailbox
– E-mail address consists of user name,
followed by @ symbol, then domain
name of mail server
• E-mail client software on your computer
– Allows you to manage your e-mail
messages
– Features
• Address books
• The ability to attach files
• Filters
– Direct incoming e-mail to specific
folders
– Block spam
