INTRODUCTION
A Computer network is a network of computers that are
geographically distributed, but connected in a manner
to enable meaningful transmission and exchange of data
among them.
A computer network is a set of devices connected
through links. A node can be computer, printer, or any
other device capable of sending or receiving the data.
The links connecting the nodes are known as
communication channels.
The aim of the computer network is the sharing of
resources among various devices.
In the case of computer network technology, there are
several types of networks that vary from simple to
complex level.
Advantages of Network
a. The computers, staff and information can be well managed.
b. A network provides the means to exchange data among the
computers and to make programs and data available to people.
c. It permits the sharing of the resources of the machine.
d. Networking also provides the function of back-up.
e. Networking provides a flexible networking environment.
Employees can work at home by using through networks sties
through networks into the computer at office.
Components of Computer Network
Server:- This is the main or central computer of network.
All other computer are connected with this one. In the view
of power & speed, this computer is better than other
computer.
Node/Client:- All computer another than server, are
called Nodes. All the nodes has their own Name & Identity.
Comparatively powerful nodes are known as Workstation.
Network Operating System:- This software defines the
relations among the computers on a network. This also
controls the communication between nodes and
server.
Network Devices:- Repeater, Hub, Bridge, Switch,
Router & Connectors etc.
Network Card:- This is a circuit which connects
network cable to the computers. These are also known as
Ethernet Card.
Network Cable/Connectors:- The cables, which is used
to connect computers on network, are called Network
Cable. A cable connector is the component that you
attach to the end of a cable so that it can plug into a port
or an interface of an electronic system.
Computer Network Architecture
Computer Network Architecture is defined as the physical
and logical design of the software, hardware, protocols, and
media of the transmission of data.
Simply we can say that how computers are organized and
how tasks are allocated to the computer.
Peer-To-Peer Network Architecture
Peer-To-Peer network is a network in which all the
computers are linked together with equal privilege and
responsibilities for processing the data.
Peer-To-Peer network is useful for small environments,
usually up to 10 computers.
Peer-To-Peer network has no dedicated server.
Client-Server Network Architecture
Client/Server network is a network model designed for the
end users called clients, to access the resources such as songs,
video, etc. from a central computer known as Server.
The central controller is known as a server while all other
computers in the network are called clients.
A server performs all the major operations such as security
and network management.
A server is responsible for managing all the resources such as
files, directories, printer, etc.
All the clients communicate with each other through a
server. For example, if client1 wants to send some data to
client 2, then it first sends the request to the server for the
permission. The server sends the response to the client 1 to
initiate its communication with the client 2.
TYPES OF COMPUTER NETWORK
➢ Local Area Network(LAN)
➢ Metropolitan Area Network(MAN)
➢ Wide Area Network(WAN)
Local Area Network (LAN)
❖ A Local Area Network (LAN) is a computer network covering
a small geographic area, like a home, office, or group of
buildings.
❖ LAN is owned by a single organization because of its limited
area.
❖ LAN is used for connecting two or more personal computers
through a communication medium such as twisted pair,
coaxial cable, etc.
Metropolitan Area Network (MAN)
❖ A Metropolitan Area Network (MAN) is a computer network
covering a town or city.
❖ MANs are larger LANs in terms of geographic area covered.
❖ MANs use high speed connections using coaxial cable and
microwave links.
❖ Best example of MAN is Cable Television network in many
cities.
❖ MAN is formed by connections several LANs which may
belong to various organizations.
Wide Area Network (WAN)
❖A Wide Area Network (WAN) is a computer network
covering a very large geographic area, like a country.
❖ WAN uses very high speed communication links like
satellite communication, telephone lines and
microwave links.
❖A Wide Area Network is not limited to a single location,
but it spans over a large geographical area through a
telephone line, fibre optic cable or satellite links.
LAN, MAN & WAN
➢ Network in small geographical Area (Room , Building or a
Campus) is called LAN(Local Area Network)
➢ Network in a City is call MAN (Metropolitan Area
Network)
➢ Network spread geographically (Country or across Globe)is
called WAN(wide Area Network)
Computer Network Criteria
Performance: Performance is the defined as the rate of
transferring error free data.
Reliability: Reliability is the measure of how often a network
is useable.
Security: Security is the protection of Hardware, Software and
data from unauthorized access.
