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A computer network is a system of interconnected computers and peripheral devices. For example, it may connect computers, printers, scanners and cameras.

Using hardware and software, these interconnected computing devices can communicate with each other through defined rules of data communications. In a network, computers can exchange and share information and resources.

A computer network may operate on wired connections or wireless connections.

When two or more networks are linked or connected and are able to communicate with one another using suitable hardware and software, it is called an internetwork.

Therefore, in order to makecommunications possible fromcomputers, across telephonesand radios and back to computers and other digital devices again, there must be a signal translator, which we call – a modem.

The modem, which is short for modulator or demodulator,converts digital signals intoanalog and back again intodigital signals for information tomove across the telephone line.


In order for a network to properly operate, two categories of network
communications components are needed; ‘Hardware’ and ‘Software’.

Computers, hub, switch, router,
network interface cards and both
wired and wireless communications
media fall under the ‘Hardware’category.

Operating systems and applications fall under the ‘Software’ category.


Signals which carry information
in a communications system
travel through a physical medium.

This physical medium is called
a communications channel, or at
other times a communications
link, a communications line, or
a communications medium.

Some common types of network
communications channels are the:
twisted-pair wire
coaxial cable
fiber-optic cable
satelite systems
wireless systems (namely using radiowaves, microwaves and infrared)


The Network Interface Card or NIC is one of the most important communications devices for a PC.

The NIC provides connection
between the computer and the
network’s communications media.

This connection is necessary because the NIC functions as a data conversion device to move data from the PC’s system to the network medium and vice versa.

The Network Interface Card alsosupplies the basic addressing system used to get data from PC to PC across a network. The other hardware component that is required for communications to work on a network is the networking device, such as the hub, switch, router and even the modem. The function of these devices is
generally to control the flow of data on a network.

The client computers are computers on the network that rely on the server for its resources and services.

Client computers send requests to a server for resources or services to perform their job. For example, a client computer can send a request asking permission to use the printer attached to the server, to print a document.

Usually a client computer has to log onto the network using a user name and password to use the server’s resources and services.

For example, you have to be a TMnet or Jaring member to use the internet service. You need to logon to TMnet or Jaring’s server by sending your username and password.

After your successful login process, then you can access the internet through TMnet or Jaring’s server.


Peer-to-peer (P2P) network is a network with all the nodes acting as both servers and clients. A PC can access files located on another PC and can
also provide files to other PCs.

P2P network is easier to manage as long as there are network cards installed on the PCs and connection can be done with a network cable. To share the resources, each PC must have the necessary program.

There is no central server or central router managing a P2P network.

Wireless networking can be an
example of a P2P network as
you only need a wireless card,
connect it to an existing wireless network and resources can be shared

Limewire, Bearshare and Kazaa are all examples of software applications for peer-to-peer (P2P) file sharing.

Copyright 2010 ict