Internet, Intranet and Extranet

Internet, intranet, and extranet are three terms that describe "Internet type" applications that are used by an organization, but how do you know if a web application is part of your intranet or part of the Internet?

• INTERNET:

The Internet is a global system of interconnected computer networks that use the standard Internet Protocol Suite (TCP/IP) to serve billions of users worldwide.

• INTRANET:

An intranet is a private computer network that uses Internet Protocol technologies to securely share any part of an organization's information or operational systems within that organization.

• EXTRANET:

An extranet is a private network that uses Internet protocols, network connectivity. An extranet can be viewed as part of a company's intranet that is extended to users outside the company, usually via the Internet.

Internet	Intranet	Extranet
It is a Global system of interconnected computer network.	It is a Private network specific to an organisation.	It is a Private network that uses public network to share information with suppliers and vendors.
Not regulated by any authority.	It is regulated by an organization.	It is regulated by multiple organization.
Thus content in the network is accessible to everyone connected.	Thus content in the network is accessible only to members of organization.	The content in the network is accessible to members of organization & external members with access to network.
It is largest in terms of number of connected devices.	It is small network with minimal number of connected devices.	The number of devices connected is comparable with Intranet.
It is owned by no one.	It is owned by single organization.	It is owned by single/multiple organization.
It is means of sharing information throughout the world.	It is means of sharing sensitive information throughout organization.	It is means of sharing information between members and external members.
Security is dependent of the user of device connected to network.	Security is enforced via a firewall.	Security is enforced via a firewall that separates internet & extranet.
Example: What we are normally using is internet.	Example: TCS using internal network for its business operations.	Example: HP and Intel using network for business related operations.
Users can access Internet anonymously.	Users should have valid username/password to access Intranet.	Users should have valid username/password to access Extranet.
Internet is unregulated and uncensored.	But Intranet is regulated by the organization policies.	Extranet is also regulated by contractual agreements between organizations.

DID YOU KNOW?

Ringworm is not caused by worms, but by fungi of several different species that infect the skin of humans and many other mammals.

Leo Fender, founder of the iconic Fender Electric Instrument Manufacturing company, couldn't play the guitar. 

If you were injured by electricity (but not killed), you were merely shocked; electrocution is a portmanteau of the words electrical and execution, and only applies when the person is killed by the electrical shock. 

Abraham Linclon, 16th president of the United, and Charles Darwin, best known for his contributions to the field of evolutionary theory, were both born on February 12, 1809. 

The 1971 cult classic film Willy Wonka & The Chocolate Factory was financed by food mega-conglomerate Quaker Oats to promote their Wonka Bars; the bars proved unpopular and were off the shelves within a year, but the popularity of the movie endures. 

There are 292 ways to make change for a  U.S. Dollar bill using U.S. coins (293 if you consider exchanging a dollar bill for a dollar coin to be "making change").

Just like we orbit around the sun, our sun orbits around the center of the Milky Way galaxy; a "sun year" is a very, very long time, however, as the sun is 26,000 light years from the center of the galaxy and completes an orbit only once every 226 million years.

Astronaut sleeping areas require good ventilation; in the micro gravity environment exhaled carbon dioxide can pool around the sleeping astronaut's head if it is not pushed away by fresh air. 

The Shure SM57 is one of the best selling microphones in the world and, in addition to wide use in live performance and studio recording, has been used for the public speaking engagements of every U.S. President since its introduction in 1965.

Falling coconuts kill more people every year than shark attacks. 

Oysters change their gender once or more over the course of their lifetime.

Prolonged internal exposure to elemental silver, as with heavy long-term use of colloidal silver treatments, can turn the user's skin permanently blue.

Although advertised as having "billions and billions" of possible configurations, in reality a Rubik's Cube actually has a staggering 43.25 quintillion potential configurations. 

The first country to acknowledge women's right to vote was New Zealand, in 1893.

Click to download pdf of Networking chapter

Networking

Basic of Networking

COMMUNICATION
Communication describes a process in which two or more computer or devices transfer data, instructions and information.

ADVANTAGE OF COMPUTER NETWORKING

• sharing of devices such as printer and scanner
• sharing of program/software
• sharing of files
• sharing of data
• Sharing of information
• Sharing of single high-speed internet connection
• Can access server centered database
• Better communication using internet services such as email, mailing list and Internet Relat Chat (IRC)

DISADVANTAGE: 

• High cost of installation.
• Requires time for administration.
• Failure of server.
• Cable faults.

OR

NETWORK BENEFITS

The network provided to the users can be divided into two categories:

1. Sharing
2. Connectivity

Sharing Resources :-

Hardware: A network allows users to share many hardware devices such as printers, modems, fax machines, CD ROM, players etc.

Software: Sharing software resources reduces the cost of software installation, saves space on hard disk.

COMPONENTS OF COMPUTER NETWORK

• Two or more computers.
• Cables as links between the computers.
• A network interfacing card (NIC) on each computer.
• Switches
• Software called operating system (OS).

DIFFERENCE BETWEEN CLIENT/SERVER AND PEER-TO-PEER 

Client/Server

• Server has to control ability while client's don't.
• Higher cabling cost.
• It is used in small and large networks.
• Easy to manage.
• Install software only in the server while the clients share the software.
• One powerful computer acting as server.

Peer-to-Peer

• All computers have equal ability.
• Cheaper cabling cost.
• Normally used in small networks with less than 10 computers.
• Hard to manage.
• Install software to every computer.
• No server is needed.