Transcript WWW(updated) - PITSiNET

Chapter 1a
Introduction to Internet and World
Wide Web
Part I
Terms & Definitions
Client
A client is the requesting program
in a client/server relationship, e.g,
the user of a Web browser is
effectively making client requests
for pages from servers all over the
Web.
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Terms & Definitions
Server
In general, a server is a computer
program that provides services to
other computer programs in the
same or other computers.
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Terms & Definitions
Web browser:
The web client, called a browser, is
the software that allows you to
interact with information available
on the Internet. e.g Netscape
Navigator, Microsoft Internet
Explorer, MOSAIC.
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Terms & Definitions
HTML (Hypertext Markup
Language):
HTML is a tagging language used to
compose documents that will be viewed
by a web browser.
It is a standard adopted so that no matter
what computer platform someone is
using, the web browser knows how to
display the web document.
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Web Page:
A mixture of text, graphics, sound and
animation in the HTML format, to make
information accessible in a easy to
understand format using the Internet.
Web Site:
A collection of web pages connected (linked)
by Hypertext clickable links.
Web Site Storage/Hosting:
After a web site is designed it must be stored
on a computer that can be accessed through
the Internet and the World-Wide Web .
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PROTOCOL:
It is a set of conventions governing the
processing and especially the data in an
electronic communications system.
TCP/IP (Transmission Control
Protocol/Internet Protocol ):
TCP/IP is a set of protocols developed
to allow cooperating computers to
share resources across a network.
They provide a few basic services that
everyone needs (file transfer,
electronic mail, remote logon, etc…)
across a very large number of client
and server systems.
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URL (Uniform Resource Locator):
The URL is a "standard" way of easily
expressing the location and data type
of a resource. URLs in general take
the form "protocol://address" where
protocol is something like HTTP, FTP,
telnet, and so on, and the address is
merely the server name of a given
resource or page.
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DNS (Domain Name Services):
DNS refers to a network service that
associates host names (alphanumeric) with
their equivalent TCP/IP address. This is done
by the means of a standard look-up table.
Example:
Translation from domain names:
http://www.afterzed.com/ into correct TCP/IP
addresses, e.g. 65.108.17.93.
Telnet :
Telnet is the way you can access someone
else's computer, assuming they have given
you permission.
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SMTP (Simple Mail Transfer
Protocol):
SMTP is the standard protocol used to
exchange Internet mail between
TCP/IP hosts. “Message Handling
Systems”
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Domain (s)


On the Internet, a domain is basically a
registration category identifying geographic
or purpose commonality.
There are seven top-level domains currently
in use:

com - A commercial organization. The
largest domain extension currently used.

edu - An educational establishment such
as a school or university.

gov - A branch of the U.S government that
is strictly reserved for that purpose.

int - An international organization such as
the United Nations.
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Domain (s) (Cont.)
net - A network organization.
 org - A non-profit organization.
 mil - A branch of the U.S military
that is strictly reserved for that
purpose.
In other parts of the world the final
part of the domain name represents
the country in which the server is
located like my for Malaysia, bb for
Barbados, ca for Canada and uk for
Great Britain.


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Internet:



At its most basic level, the Internet is an
utility connecting localized computer
networks (that might exist in a lab, in a
building, in a department, or on a campus)
with computer networks that extend across a
wider area, like a region or a continent.
Technically, what distinguishes the Internet is
its use of a set of protocols called TCP/IP.
Two recent adaptations of the Internet
technology are the Intranet and the
Extranet.
The term 'Internet' comes out of the
concept of 'internetworking'
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World-Wide Web:
The World-Wide Web (WWW) is a
pair of software applications,
which allow both distribution of
and access to information on the
Internet. The web is not the
Internet but a means of
distributing and accessing the
information that is on it.
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E-COMMERCE / E-BUSINESS:

"E-Commerce" (Electronic Commerce or
EC) is the buying and selling of goods
and services on the Internet, especially
on the World-Wide Web.
 Example of E-Commerce Website:
Blooming-Online Florist
(http://www.blooming.com.my)
Amazon.com
(http://www.amazon.com)
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FIRE WALL:


A firewall is a program, usually an Internet
gateway server, that protects the resources of
one network from users from other networks.
Any enterprise will want a firewall to prevent
outsiders from accessing its own private data
resources.
There are a number of firewall screening
methods. A simple one is to screen requests to
make sure they come from acceptable domain
names and IP addresses. Another is to not
allow Telnet access into your network except
for your own users.
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Firewall
INTERNET
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HTTP:
The Hypertext Transfer Protocol is the set
of rules for exchanging files (text, graphic
images, sound, video, and other
multimedia files) on the World Wide Web.
www.fluvius.co.uk/faq_glossary/glossary.htm
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HTTP (HyperText Transfer Protocol):
User request document from browser.
6
1
BROWSER
Display web page.
USER
5
Send request.
Send response.
3
Open connection of web server.
2
WEB SERVER
4
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Searching for the document.
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Web Server:


Stores and transmits web documents (files). It
uses the HTTP protocol to connect to other
computers and distribute information.
Example: IIS, Apache, Sun Java System Web
Server
FTP (File Transfer Protocol):



FTP is the standard used to transfer files over
the Internet.
FTP allows you to copy any kind of computer
file (text, software, images, sounds, fonts,
etc...) from one computer to another via a
network using the Internet.
FTP is not platform-specific, so as long as you
have a computer (DOS, Macintosh, Unix, etc.)
that is connected to the Internet, you can copy
files.
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ISP (Internet Service Provider):



An ISP is a company that provides
individuals and other companies access
to the Internet and other related
services such as Web site development
and hosting (web site storage).
The larger ISPs have their own highspeed leased lines so that they are less
dependent on the telecommunication
providers and can provide better service
to their customers.
List of Internet Service Providers in
Malaysia
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Java Applet:



An applet is a small program run on
the Web, using Java, the objectoriented programming language.
It can be can be sent along with a
Web page to a user.
It can perform interactive animations,
immediate calculations without having
to send a user’s request back to the
server.
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Java Applet- Examples



Football Game
Traffic Simulation
Inner Solar System Model
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XML (eXtensible Markup
Language):


XML is a flexible way to create
information formats and shared on the
World Wide Web, intranets, and
elsewhere,
Example, computer makers might agree
on a standard or common way to
describe the information about a
computer product (processor speed,
memory size, …) and then describe the
product information format with XML.
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XML (eXtensible Markup
Language):


Such a standard way of describing data
would enable a user to send an
intelligent agent (a program) to each
computer maker's Web site, gather
data, and then make a valid
comparison.
XML can be used by any individual or
group of individuals or companies that
wants to share information in a
consistent way.
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XML (eXtensible Markup Language):


XML is currently a formal recommendation
from the World-Wide Web Consortium
(W3C) as a way to make the Web a more
versatile tool.
XML is similar to the language of today's Web
pages, HTML in that both contain markup
symbols to describe the contents of a page or
file. HTML, however, describes the content of a
Web page (mainly text and graphic images)
only in terms of how it is to be displayed and
interacted with. Example: a <P> starts a new
paragraph.
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XML (eXtensible Markup
Language):


XML describes the content in terms of
what data is being described. e.g., a
<PHONENUM> could indicate that the
data that followed it was a phone
number.
This means that an XML file can be
processed purely as data by a program
or it can be stored with similar data on
another computer or, like an HTML file,
that it can be displayed.
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How XML codes look like
<note> <to>Tove</to> <from>Jani</from>
<heading>Reminder</heading>
<body>Don't forget me this
weekend!</body> </note>
To understand more about XML:
W3Schools- Learning XML
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History of the Internet:
•
•
•
•
The Internet grew out of many
developments in computer networking and
telecommunications research.
Early projects undertaken in early 1960’s by
the US military (known as DARPAnet).
Started with a dozen of Networked computer
systems of universities and institutions,
allowing computers to be shared.
Allowing fast communication between
researchers through Emails.
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History of the Internet (Cont.)
•
•
•
Only people in the government, military and
academic had access to the network.
In 1991, the National Science Foundation
(NFS) gradually started backing off from its
subsidy of the backbone network, then
allowed commercial access to the internet.
With commercial access to the Internet,
businesses and all kinds of agencies began to
use the Internet to communicate, exchange
data and distribute information;
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History of the Internet (Cont.)
•
A host of businesses called Internet
Service Providers (ISPs) sprang up.
ISPs provide dialup access to the
Internet; an individual or a business
opens an account with the ISP, dials
into the ISP's computer and via the
ISP's computer connects to the
Internet.
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History of the Internet (Cont.)
•
Internet traffic grew,
 Many businesses spent heavily to
improve the internet, therefore to
better service their customers.
 Big competition among
communication carriers, hardware
and software suppliers.
 As a result, Internet’s bandwidth
climbed high, & cost went down!
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History of the World-Wide Web
•
WWW allows computer users to locate
and display multimedia-based
documents,
•
Introduced in 1990 by Tim Berners-Lee
of CERN (Geneva).
•
Today’s Internet mixes computing and
communications technologies.
•
It makes our work easier.
•
It is changing the nature of the way
business is done.
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History of the World-Wide Web
(Cont.)
•
It makes information instantly and
conveniently available to anyone with a
connection
•
Communities can stay in touch with one
another.
•
Researchers can learn of scientific and
academic breakthroughs worldwide.
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2. Internet Applications
Internet Protocols
HTTP (HyperText Transfer Protocol):
which are the basis for information
exchange on the Internet), HTTP is an
application protocol.
HTTPs (“s” stands for security):
is the same way as HTTP but used
securely.
•
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FTP (File Transfer Protocol)
Telnet
Other alternative in the Market:
Terminal Services, PC Anywhere
•


Email (Electronic Mail)
E-mail is the exchange of computerstored messages by telecommunication.
you can send messages (text, graphic
images and sound files) as
attachments.
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•



Email (Electronic Mail) (Cont.)
E-mail was one of the first uses of
the Internet. Probably it is still the
most widely used internet
application.
A large percentage of the total
traffic over the Internet is e-mail.
It uses Simple Mail Transfer
Protocol or SMTP.
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•

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Search Engines
Web sites that sort through by
keywords and categories:

Google (www.google.com)

Yahoo (www.yahoo.com)

Lycos (www.lycos.com)

Altavista (www.altavista.com)
Store information in databases.
Returns list of sites as hyperlinks.
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•

Search Engines (Cont.)
Meta-search engines:

No Database maintenance.

Combine results from multiple search
engines.

Microsoft MSN: www.msn.com

IE5.5 has a built-in meta-search
engine that is accessed by clicking the
search button on the toolbar.
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3. Internet Architecture &
Topologies
•
Internet Service Providers
(ISPs)



To get to the internet we need to pay
“people at access points”, are the ISPs
Because they have high speed
connections to the internet, and
dedicated hardware.
They sell their services back to users
like Email, web storage, slower internet
access dialup Chap1a
or dedicated
line.
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•

Internet Service Providers
(Cont.)
Commercial ones out there:
www.aol.com,
join.msn.com,
www.NetZero.com, …
www.Guno.com, …
…..
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•
Domains
Internet registration category identification for
geographic and Common purposes, e.g. .com,
.com.my, others like .ac.uk, .co.uk
•


Intranets
What is an Intranet?
Intranets are private corporate information
and collaboration systems that use Internet
software and standards.
Why an Intranet
The Intranet can increase market share,
profitability, and efficiency.
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•





Why Intranet (Cont.)
Ideal place for publishing continuously
updated Corporate information.
Powerful, not expensive communications
alternative that can provide information
anywhere at anytime.
Intranet technology can be used across wide
area networks.
Web server software inter-operates well.
Web servers do not need large capital
expenditures in hardware.
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•
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How can Intranet help a company?
Intranets can be relatively easy to install, and
inexpensive to administer. Also eliminate
Printing, and out-of-date information
Procedures Manuals
Company Practices
Company phone book
Catalog and Inventory lists
Employee benefits information (Health-care
benefits)
Bulletin boards
Job Postings
In-house newsletters or publications
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•
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How can Intranet help a company?
(Cont.)
Training
Presentations
Order Processing
Expense Report
Sales Force Automation ( Offsite employees
conducting sales, marketing, … can access all
the companies information remotely easily and
in a cost effective way)
Help-desk and technical support
Company suppliers information (What each
supplier is quoting at each specific location)
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•



How can Intranet help a
company? (Cont.)
Access search and sort database records
dynamically by converting databases to
HTML on the fly, in SQL or other formats.
Sort through thousands of documents
and quickly retrieve the information you
need with the proper search engine.
Video Conferencing
Putting such applications on an Intranet
can serve a large group of users at a
substantially low cost.
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•
Example of Intranet
College IT Information Portal
(http://coit.uniten.edu.my/)
Student Project Management System-Diploma
(http://sephiroth/CPRD383/)
Student Project Management System-Degree
(http://sephiroth/spmsv2/)
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•
Extranets
What is an Extranet?

An Extranet is a collaborative network that
uses Internet technology to link businesses
with their suppliers, customers or other
businesses that share common goals.

An Extranet can be viewed either as part of a
company's Intranet that is made accessible to
other companies or as a collaborative Internet
connection with other companies.

The shared information can be accessible only
to the collaborating parties or can be publicly
accessible.
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Extranet applications (some
examples):

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


Private newsgroups that cooperating
companies use to share valuable experiences
and ideas.
Training programs or other educational
material that companies develop and share.
Shared product catalogs accessible only to
wholesalers or those "in the trade".
Project management and control for
companies that are part of a common work
project.
An Extranet usually requires a degree of
security and privacy from competitors.
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Example of Extranet
TNB Livewire
(http://livewire.hq.tnb.com.my)
Maybank2U.com
(http://www.maybank2u.com.my)
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Using Forum
How to Post a Question
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