COMPARISON BETWEEN INTRANET, EXTRANET AND INTERNET

Intranet

An intranet network is only available to a small group of people. Intranets are mainly used within businesses and organizations to provide access to files and applications among networked computers and servers. Intranets may or may not have access to the Internet. If an intranet does connect to the Internet, a firewall is used to prevent outside access to the intranet. The purpose is to allow people within the same company to share information over a local area network. It is sometimes referred to as a private Internet.

Extranet

An extranet is similar to an intranet, but is accessible via a Web portal. An extranet may be accessed from anywhere if the user has a valid user name and password. The purpose of this type of network is to allow collaboration and sharing of resources not only in-house but with a select group of outside users. For instance, businesses will use an extranet to allow customers to log in to provide input on projects. Another example is using a virtual private network to allow employees to log in to the network when they're are not in the office.

Internet

The Internet is a network that is available to anyone with an Internet-connected device. It is a massive collection of networks sharing information publicly in the form of interlinked Web pages. Internet Protocol defines a site's unique location which most users see as a domain name or URL. The network is literally world-wide and is often referred to as the world wide web.

THE INTERNET

Definition

a global computer network providing a variety of information and communication facilities, consisting of interconnected networks using standardized communication protocols.

Advantages Of Internet

1) Information on almost every subject imaginable. 

2) Powerful search engines

3) Ability to do research from your home versus research libraries. 

4) Information at various levels of study. Everything from scholarly articles to ones directed at children. 

5) Message boards where people can discuss ideas on any topic. Ability to get wide range of opinions. People can find others that have a similar interest in whatever they are interested in. 

 

Disadvantages Of Internet

1) There is a lot of wrong information on the internet. Anyone can post anything, and much of it is garbage.  

2) There are predators that hang out on the internet waiting to get unsuspecting people in dangerous situations. 



3) Some people are getting addicted to the internet and thus causing problems with their interactions of friends and loved ones.

4) Pornography that can get in the hands of young children too easily.
 
5) Easy to waste a lot of time on the internet. You can start surfing, and then realize far more time has passed than you realized. Internet and television together of added to the more sedentary lifestyles of people which further exacerbates the obesity problem. 

3.1.4 Network Classification

 LAN

Network thats connects computers and devices in a limited geographical area.

Area - confine to a single building

Ownership - Controlled and managed by a single person or organization

example  - Network in Computer Lab

                - Network in a home

MAN

A high speed network that connects local area networks in metropolitan area

Area : Cover multiple buildings in a city (metropolitan city)

Ownership : Single entity such as government body or large corporation

Example : Traffic Light

                  Network use for bank

WAN

Network that connects computers and devices in a large geographical area

Area : Cover any size geographical area (country wide or worldwide)

Ownership : Own by organization which exist under distributed ownership and management over long distance

Example : The Internet

3.1.1 Basics Concept of Network

DEFINITION 

NETWORKING

Network devices including switches and routers use a variety of protocols and algorithms to exchange information and to transport data to its intended endpoint. Every endpoint (sometimes called a host) in a network has a unique identifier, often an IP address or a media access control address, that is used to indicate the source or destination of the transmission. Endpoints can include servers, personal computers, phones and many types of network hardware.

COMMUNICATION DEVICE

A communication device is a hardware device capable of transmitting an analog or digital signal over the telephone, other communication wire or wirelessly

COMPUTER COMMUNICATION

The transmission of data from one computer to another, or from one device to another. A communications device, therefore, is any machine that assists data transmission. For example, modems, cables, and ports are all communicationsdevices.

Type of Computer Communication

Modem -  A modem is an external or internal device thats function is to transmit digital dataover communication lines.Traditional modems once used frequently with dial-up networks convert analog data from telephone lines into computer digital data.

Network Card - Enables a computer or devices that does not have built in networking capability to access a network

Wireless Access Point - A central communications devices that allows computers and devices to transfer data wirelessly among themselves or to transfer data wirelessly to a wired network

Router - Connects multiple computers or other routers together and transmits data to its correct destination on a network

Hub - Provides a central point for cables in a network, receives data from many directions and then fowards it to one or more destinations.

TRANSMISSION MEDIA

materials that capable of carrying one or more signal from one system to another

TYPE OF TRANSMISSION MEDIA

 Physical transmission Media   

use wire, cable, and other tangible to send communication signals 

   

Wireless Transmission Media                            

send communications signal through the air or space using radio, micro wave.