Network: - A group of computers that are connected to each other for the purpose of sharing computer software & hardware resources between many users.

Or

Joining two or more computers each other is called network.

Like: - CD drive, hard disk drive and sharing information is called network.

Networking: - Sharing data over the network is called networking.

Need for networking: - Now a day, It plays the most important role in our modern life because without networking we cannot connect one people to another people and one organization to another organization quickly.

Communication technology has entered into the face because all the media are interconnected. Some of popular modes of communication are: -

Ø Talking

Ø Letter

Ø Telegrams

Ø Telephone

Ø Fax machine……………..etc.

Data communication networks: - It has become possible mainly because of computer. This technology involves transfer information in the form of object. Like: - text, picture, sound…etc. computer is the device that allows user to send and receive this object. Computer networking is the best sources for data communication as local & global.

When the computer is inter-connected the user of these machines can share data stored in computer. Data is either in primary & secondary.

Type of networking: - Networking has been developed on several labels from local & international in diverted sector of society.

Networks used by government organization for referred travel information from database, at banks sector, merchant etc.

 

There are many types of computer networking as given below: -

Ø LAN (Local Area Network)

Ø WAN (Wide Area Network)

Ø MAN (Metropolitan Area Network)

LAN (Local Area Network): - A system of network computer and other hardware like: - printer that are relatively close proximately to one other. LAN networking type used for local area network like one computer to another computer, room, a single building, a ship or an aircraft.

Note: -

o   Transfer data at high speed

o   They exist in a limited geographic area

o   Their technology is generally less expensive 

WAN (Wide Area Network): -A Wide Area Network is a data communication network that work is one state to another state. It is a geographical communication network and its works in railway station, banking sector, and big organization…….etc. It connects with router to use this network.

MAN (Metropolitan Area Network): -A Metropolitan Area Network is a basically bigger version of a LAN and normally uses similar technology. It might cover group of corporate office or cities and might be entered provide or public. A man can support both data and voice and might even to relate to the local cable television network.

MAN provides to the network very high speed and its use manually a metropolitan city. It works same as CAN (Campus Area Network).

 

Network Topologies: -A network topologies is a geometry arrangement of nodes and cables link in a LAN and it used in two general configurations i.e. Bus and Star topologies.

This two topologies define how does connected to one another. A node is an active device connected to the network such as computer or a printer.

Topologies are a physical layout of the network which provides another way to differentiate between networks. Different network topologies offered different advantage in cost complex sting.

There are three type of network topology: -

Ø The Bus topology

Ø The Ring topology

Ø The Star topology

The Bus topology: -It is the simplest of all topologies in the layout the network being at one end and then connects to each other for ex.

People often referred to this as daisy changing to computer together. It is useful and easy to put together for a small class room or lab network.

The Ring Topologies: -The next topology used in networks is the ring topologies. It is very similar to the bus topology accept that the two ends of the networks connect to for a complete ring foe ex: -

The chief advantage of topologies over bus topologies is that if break occurs in the ring computer network will still be able to communicate by going to the other way around the ring.

The Star Topologies: -In this layout the network designers design one location as the center of the start. Network architecture consist a central HUB (electronic device with multiple slots to connect more than one computer). The Star topologies are often used within a LAN.

In a star network several device are connected to a device.

Component of Network: -The computer network is a system that has several devices for gathering data processing and distribution.

The components of network are for LAN: -

Ø The workstation & the Server

Ø NIC (Network Interface Card)

Ø HUB

Ø Switch

Ø Cables

Ø RJ-45 Connector

Server: -A network storage data can be used by many user. The computers that are responsible to store all the data and also to update information is called server.

Its function stores all files in the system that may either contain program or data. It also makes those data available for the user. Since its storage data is in the form of files, it referred to as file server.

 

The Workstation: -The computer that are responsible to accept the user inputs, add transfer the data to the server for processing are called workstation.

The workstation can access all resources of the server. These resources include the CPU, Memory, Input/output device……..etc.

 

NIC (Network Interface Card): -It is an electronic card which used to connect wire (Networking wire with PC and HUB & Server).

 

HUB: -It is an electronic device which used to connect with Workstation. It is responsible to accept transfer data between workstation.

Cables: -A flexible metal/wire used in a line of communication is called cables.

There are various kinds of cable: -

Ø Twisted Pair Cable

Ø Co-Axial Cable

Ø Fiber Optics Cable

 

Twisted Pair Cable: -It is used for telephone. They contain two wire of conducting material include from each other. They appear twisted hence the name.

It includes the following layer: -

a)     The inner layer is a conductor of wire covered by the insulating material. The conductor is generally made up of copper.

b)    The middle layer is including layer repairing the inner section from the other layer.

c)     The outer layer conductive material that is in the form of mesh surrounding the insulating tube.

 

Co-Axial Cable: -It is used to transmitting data information from various workstations. The cable transmits efficiently over a limited geographic area generally a LAN.

Fiber Optic Cable: -It is used to carry data and information and transmit then in the form of light rays. They are free only any outside interface like noise.

It is capable of transmitting data in huge volume and high speed. The chances of data being cropped threw the transmitting line are very less.

 

Software: -software is a programmed instruction or code where user can access any type of information that means user can work upon any application software.

There are three type of software: -

Ø System Software (Operating System)

Ø Application Software (Ms-Office, Tally, C language….etc)

Ø Utility Software (Antivirus)

These facility are provide by a group of software programmed called the network operating system.

The services provide by a network operating system are: -

a)     Storage and retrieval of files

b)    Keeping information secure

c)     Access to its resources by multiple user of the system

d)    Identifying and connecting various workstations with the server.

User: -There are two type of network user: -

Ø The system administrator

Ø The End User

The System Administrator: -The computer networks are large and complex system made up of the server and multiple workstations like any other system it required a manager. The person who keeps a track of the problems in the system and rectifies them is called the system administrator

Its job include: -

a)     Creating user and managing them.

b)    Providing access of resources to its users.

c)     Protecting the network from unauthorized access.

d)    Any other external user of the system should not edit and make changes to the data and resources of the user or the system.

The End-User: -The End-user is the people who access the network from the workstation. Each user has own separate workstation. The different end user can be broadly classified as: -

Ø Data entry operator

Ø Application user

Ø Programmers

Unit - 2

Advantages of Networking

As we know very well Networking is the most useful technology field due to workstation. Networking system helps to do any type of official task and find out about the specific topic easily. There are many branches of an organization in different place and that organization maintain all official requirements i.e. accessing of data and transaction of product ………….etc. based on networking system.

                   There are following advantage of networking: -

Ø Exchange of Data

Ø Access of Internet

Ø Sharing & Resources

Ø Creating Backup

Logging in: -The process of connecting your computer or workstation to a specific server is called Logging In.

Logging out: -The Log out command breaks the connection to the server after logout the computer exit from the server.