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A network of networks
Internet is a network made of lots of interconnected networks.
It is a wide area network. (WAN)
It is a wonderful and surprising achievement in the field of computer science.
Internet support companies, and just about every type of other organization.

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The Internet began in 1969, as an experimental four– computer network called ARPA (Advanced Research
Project Agency), which was designed by the U.S Defense
Department so that research scientist could communicate
. In approximately two years , ARPAnet grew to about two dozen sites and by 1981, consisted of more than two hundred sites . In 1990, ARPAnet was officially disbanded and the network , which know consisted of hundreds of sites , came to known as the Internet.

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There is no particular organization that controls the Internet.
Different networks of private companies , government agencies , research organizations
, universities etc are interconnected together.
Internet is a huge collection of millions of computer, all linked together on a network.
Network allows all the computers to communicate with each other.
A home computers are connected to the internet using phone line modem DSL (Digital
Subscribe Line) or cable modem that communicate to ISP( Internet service providers)

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ISPs then connect to the large ISPs , and the largest ISPs maintain fiber-optic backbones” for entire region.
Backbones around the world are connected through the fiber-optic lines, under sea cables or satellite links.
In this way every computer on the Internet is connected to every other computer on the the
Internet.
ISP: It is a company that provides the internet connection to the users . There are many ISP companies in each big cities of each country of the world.

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Intranet:
An organization network through which files and messages are exchanged among the users of an organization only is called the Intranet.This type of network uses the same protocol as used in the Internet. but through the intranet the information can not exchanged outside the organization.
Extranet :
An extranet is a network of multiple intranets . It means that different companies are connected together for the collaboration among the companies. On an each extranet each company connected gives selected rights to employees of one or more other companies to access its intranet in order to communicate and share information and ideas relevant to that companies.

The internet provide a number of services such as :
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World Wide Web
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Chatting
News Groups
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Electronic E-mail
FTP
Electronic E-Commerce

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The world wide web is the fastest growing part of the internet.
The World Wide Web is a world wide information service on the internet.
This is a graphical environment that allows the text and pictures to be displayed on your screen.
WWW uses special software called web
Browsers and TCP/IP, HTTP(Hyper Text
Transfer Protocol)and a web server to function.

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People are talking to other people all around the world.
They enter to the chat room in order to chat with other people.
They send messages to each other, discuss ideas and events.
They are using different services like
MSN Messenger and Yahoo Messenger.

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News groups are included in internet.
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They can be access with the help of your
Internet Browsers and enable us to take part in the discussion of interest with likeminded people from around the world.

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This service is available over the internet enabling to send and receive the messages on the global basis.
People uses e-mail for anything for which they might uses paper mail, faxes , special document or telephone lines.
You can communicate globally for the cost of local phone call.
The reason for this is that you are connected to the internet through ISP by dialing a local dialup numbers.

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FTP is simply a way to transfer the files to and from the internet.
FTP is not just a protocol but also as a service and an application.
FTP provides the facility to transfer the files between two computers running different operating system .
FTP is a service for copying the files from one computer to another computer.
For two computers to actually make use of the service of FTP , both computers requires a special application software.FTP is an application for copying files

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This is the modern way for selling and buying goods over the internet in a secure manner.
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Credit cards are used for payment.
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Many services are available for handling credit cards over the internet with security .

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The purpose of the internet is to established a connection between large numbers of computers all over the world. Computer can send and receive the data to each other.
On the Internet every computer has a unique address with a reference of this address a computer can communicate with other computer on the internet. There are two types of addressing schemes recognized on internet .
IP addressing
DNS addressing

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IP stands for internet protocol.
It is a unique identifier for a node on the Internet.
It is a numerical address with four numbers separated by dots i-e 216.27.16.137
.
For the internet to function smoothly each machine has a unique IP address
.
The four numbers in the IP address are called octets and have a value between 0 to 255.

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A server has a static IP address that does not change.
A home computer that is dialing up through a modem often has an IP address provided by ISP.
That IP is unique for the session but may be different for the next time when machine is connected.

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DNS stands for Domain Name System.
The human readable name assigned to the computer (server) on the Internet is called
Domain name.
It common and unique text name. For example,
“hotmail .com” is permanent and human readable name.
It is easier to remember than IP address.
The domain “hotmail .com” actually has two parts a host name and top-level domain(TLD). The toplevel domain represents the institution , which uses the address . It comes at the end of domain name separated with dot(.) and specifies the type of domain .

Domain
.com
.edu
.gov
.mil
.org
Type of institution
Business
Educational institutions
Government organizations
Military organizations
Other organizations

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The most important parts of the World
Wide Web are the elements such as servers , pages, hot links and more ,all of which comprises the volume of the WWW .
The following are some related terms you may see
Website
Home page
Link
HTTP
Webmaster

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Domain Name
Uniform Resource Locator
Internet Service Provider
Browser
Client
Hot list

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Web Site:
A collection of World Wide Web documents , usually consisting of a home page and several related pages . You might think of a web site as an attractive electronic book.
Home Page:
Frequently, the “ cover ” of a particular
Website . The home page is the main , or the first page displayed for an organization or person’s World Wide Web site.

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Link:
Short for “ hypertext link ” . A link provides the path that connects you from one part of World Wide Web document to another part of the same document , a different document , or another resource. A link usually appeared as a uniquely colored word that you can click to be transported to another web page.
HTTP:
Stands for Hyper Text Transfer Protocol. It is a protocol for accessing World Wide Web documents . It is primary access method for interacting with Internet.

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Stands for Hypertext Transfer
Protocol
Allows computers on the WWW to communicate with one another.
Handles the “request” sent to the
Web server and the “response” received from the Web server.

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HTML:
Stands for “ Hyper Text Markup Language ” . HTML is a coding language for the World Wide Web that informs the web browsers how to display a document text, links , graphics and other media.
This language forms the foundation for all Web pages.
Webmaster:
The individual responsible for maintaining and updating the content of World Wide document .
Webmaster are the creative forces behind the World
Wide Web.

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Domain Name:
The portion of the Internet address (URL) following the double forward slashes (//) that identifies an Internet host site . Domain name are usually two or more terms separated by periods. Some example are WWW.Isf.com.pk
,
WWW.Ucp.edu.pk
and WWW.microsoft.com
.
Uniform Resource
Locator(URL):
A URL serves as identification for all the
World Wide Web documents . It is an Internet address for locating Internet elements , such as server sites , documents , files and so on.

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Stands for Uniform Resource Locator
Also called the Web page’s address
You typically type it into your Web browser’s location bar when you want to view a Web page http://www.umbc.edu
Protocol needed to communicate with
Web server
Name of
Web server

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Internet Service Provider(ISP):
ISP is a company that sells computer access to the Internet . A user buys a subscription from
Internet service Provider, which gives the user an identifying name and password and a phone number. With his or her computer modem , the user calls and connect to and log on to the service provider’s computer. ISP also supports to high speed dial up access , such as digital subscriber line(DSL) , cable modem or a satellite
, if available in the area.

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Browsers
:
A software program that request , interprets and presents World Wide Web documents .
Frequently used Web Browsers include
Internet Explorer , Netscape Communicator ,
Mozilla Firefox.
Client:
In addition to being a computer , a client also can be software program that request and acquires information from computers that store World Wide Web documents and files.
World Wide Web Browsers are also called clients .

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Hot list:
An option available in most World Wide Web browsers that maintain a list of frequently accessed home pages. A hot list also refers to a list of home pages related to the particular subject that is published on an organization’s home page.

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A Web server is a computer that is programmed to send files to browsers on other computers connected to the Internet.
The Web browser , such as Firefox or
Internet Explorer, is the client that sends a request for a Web page.
The Web server answers the request and delivers the requested page to the browser so you can view it.

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Web pages are created using HTML syntax.
These pages must be organized and stored on central computers.
Computers which store web pages in the form of directories and files and provide these files to be read are called “Servers”.

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The server computer runs special software called “Web Server ” software that allows :
Web Site management
Accept Client’s request for information
Respond to a client’s request by providing the page with required information.
Some of the most popular software , which servers run to allow them to respond to client request for information , is Internet
Information Server (I.I.S), Apache Web
Server, Netscape server and Microsoft
Personal web Server.

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Web Clients runs special software called a
“Browsers” that allows them to
Connect to appropriate Server
Query the server for the information to be read
Provides an interface to read the information returned by the server.
Some of the most popular Browser software that clients run to allow them to query Web Servers for information is
Netscape Communicator , Internet
Explorer.

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To access information stored in the form of Web pages , users must connect to a Web Server.
Once connected , an interface that displays the contents of the Web pages is required.
Computer that offers the facility to read information stored on web pages is called “Web
Client ”.

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Introduction of different search engines.
How to Google
Using operators to make your search better
Different flavors of Google (scholars, research, images, news, etc.)

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HTTP
HTML
Web pages
Hyperlinks websites

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Launching your browser
Which browser is working on your computer.
Navigating the web
Moving from one page to another or from one website to another.
Using URLs
Web page has a unique address, called a uniform resource locator.
URLs are the key to navigate the web.

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Using Hyperlinks
Hyperlink is simply a part of a web page that is linked to URL.
A hyperlink can appear as text, an image.
Using the browser ‘s navigation tools
Web browsers offer a variety of tools to help you move around the web.
These tools can save you the trouble of typing
URLs or searching for links, and they allow you to quickly go back to pages that you have already visited.
Favourites

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Searching the web
Using search engines
Using Boolean operators in your search
Using advanced search options
Using site specific search tools.