ICT : Notes for Computer Network

INTRODUCTION


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.



NETWORK COMMUNICATION CHANNELS



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:
1. twisted-pair wire
2. coaxial cable
3. fiber-optic cable
4. satelite systems
5. wireless systems (namely using radiowaves, microwaves and
infrared)



Communications channels provide the most basic level of connectivity medium for a network.

NETWORK INTERFACE CARDS AND NETWORKING DEVICES

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 also supplies 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.