COMPUTER NETWORK BASICS

What is Computer Netwok?

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.
Computer Network uses distributed processing in which task is divided among several computers. Instead, a single computer handles an entire task, each separate computer handles a subset.
Computer Network is a group of computers connected with each other through wires, optical fibres or optical links so that various devices can interact with each other through a network.
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.
is a group of computers connected with each other through wires, optical fibres or optical links so that various devices can interact with each other through a network.
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.

Open system :-
A system which is connected to the network and is ready for communication.
Closed system :-
A system which is not connected to the network and can’t be communicated with.

Advantage of Computer Network :-

Helps you to connect with multiple computers together to send and receive information when accessing the network.
Helps you to share printers, scanners, and email.
Helps you to share information at very fast speed
Electronic communication is more efficient and less expensive than without the network.

Use Of Computer Network :-

Resource sharing: Resource sharing is the sharing of resources such as programs, printers, and data among the users on the network without the requirement of the physical location of the resource and user.
Server-Client model: Computer networking is used in the server-client model. A server is a central computer used to store the information and maintained by the system administrator. Clients are the machines used to access the information stored in the server remotely.
Communication medium: Computer network behaves as a communication medium among the users. For example, a company contains more than one computer has an email system which the employees use for daily communication.
E-commerce: Computer network is also important in businesses. We can do the business over the internet. For example, amazon.com is doing their business over the internet, i.e., they are doing their business over the internet.

Features Of Computer Network :-

Communication speed
File sharing
Back up and Roll back is easy
Software and Hardware sharing
Security
Scalability
Reliability

Communication speed :-

Network provides us to communicate over the network in a fast and efficient manner. For example, we can do video conferencing, email messaging, etc. over the internet.

File sharing :-

File sharing is one of the major advantage of the computer network. Computer network provides us to share the files with each other.

Back up and roll back is easy :-

Since the files are stored in the main server which is centrally located. Therefore, it is easy to take the back up from the main server.

Software and Hardware sharing:-

We can install the applications on the main server, therefore, the user can access the applications centrally. So, we do not need to install the software on every machine. Similarly, hardware can also be shared.

Security:-

Network allows the security by ensuring that the user has the right to access the certain files and applications.

Scalability:-

Scalability means that we can add the new components on the network. Network must be scalable so that we can extend the network by adding new devices. But, it decreases the speed of the connection and data of the transmission speed also decreases, this increases the chances of error occurring. This problem can be overcome by using the routing or switching devices.

Reliability:-

Computer network can use the alternative source for the data communication in case of any hardware failure.

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.

The two types of network architectures are used:

Peer-To-Peer network
Client/Server network

Peer-To-Peer network:-

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.
Special permissions are assigned to each computer for sharing the resources, but this can lead to a problem if the computer with the resource is down.

Advantages Of Peer-To-Peer Network:-

It is less costly as it does not contain any dedicated server.
If one computer stops working but, other computers will not stop working.
It is easy to set up and maintain as each computer manages itself.

Disadvantages Of Peer-To-Peer Network:-

In the case of Peer-To-Peer network, it does not contain the centralized system . Therefore, it cannot back up the data as the data is different in different locations.
It has a security issue as the device is managed itself.

Client/Server Network:-

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.

Advantages Of Client/Server network:-

A Client/Server network contains the centralized system. Therefore we can back up the data easily.
A Client/Server network has a dedicated server that improves the overall performance of the whole system.
Security is better in Client/Server network as a single server administers the shared resources.
It also increases the speed of the sharing resources.

Disadvantages Of Client/Server network:-

Client/Server network is expensive as it requires the server with large memory.
A server has a Network Operating System(NOS) to provide the resources to the clients, but the cost of NOS is very high.
It requires a dedicated network administrator to manage all the resources.

Computer Network Types :-

A computer network is a group of computers linked to each other that enables the computer to communicate with another computer and share their resources, data, and applications.

A computer network can be categorized by their size.

A computer network is mainly of four types:

LAN(Local Area Network)
PAN(Personal Area Network)
MAN(Metropolitan Area Network)
WAN(Wide Area Network)

LAN(Local Area Network):-

Local Area Network is a group of computers connected to each other in a small area such as building, office.
LAN is used for connecting two or more personal computers through a communication medium such as twisted pair, coaxial cable, etc.
It is less costly as it is built with inexpensive hardware such as hubs, network adapters, and ethernet cables.
The data is transferred at an extremely faster rate in Local Area Network.
Local Area Network provides higher security.

PAN(Personal Area Network):-

Personal Area Network is a network arranged within an individual person, typically within a range of 10 meters.
Personal Area Network is used for connecting the computer devices of personal use is known as Personal Area Network.
Thomas Zimmerman was the first research scientist to bring the idea of the Personal Area Network.
Personal Area Network covers an area of 30 feet.
Personal computer devices that are used to develop the personal area network are the laptop, mobile phones, media player and play stations.

MAN(Metropolitan Area Network):-

A metropolitan area network is a network that covers a larger geographic area by interconnecting a different LAN to form a larger network.
Government agencies use MAN to connect to the citizens and private industries.
In MAN, various LANs are connected to each other through a telephone exchange line.
The most widely used protocols in MAN are RS-232, Frame Relay, ATM, ISDN, OC-3, ADSL, etc.
It has a higher range than Local Area Network(LAN).

Uses Of Metropolitan Area Network:

MAN is used in communication between the banks in a city.
It can be used in an Airline Reservation.
It can be used in a college within a city.
It can also be used for communication in the military.

WAN(Wide Area Network):-

A Wide Area Network is a network that extends over a large geographical area such as states or countries.
A Wide Area Network is quite bigger network than the LAN.
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.
The internet is one of the biggest WAN in the world.
A Wide Area Network is widely used in the field of Business, government, and education.

Examples Of Wide Area Network:-

Mobile Broadband: A 4G network is widely used across a region or country.
Last mile: A telecom company is used to provide the internet services to the customers in hundreds of cities by connecting their home with fiber.
Private network: A bank provides a private network that connects the 44 offices. This network is made by using the telephone leased line provided by the telecom company.

Advantages Of Wide Area Network:-

Geographical area: A Wide Area Network provides a large geographical area. Suppose if the branch of our office is in a different city then we can connect with them through WAN. The internet provides a leased line through which we can connect with another branch.
Centralized data: In case of WAN network, data is centralized. Therefore, we do not need to buy the emails, files or back up servers.
Get updated files: Software companies work on the live server. Therefore, the programmers get the updated files within seconds.
Exchange messages: In a WAN network, messages are transmitted fast. The web application like Facebook, Whatsapp, Skype allows you to communicate with friends.
Sharing of software and resources: In WAN network, we can share the software and other resources like a hard drive, RAM.
Global business: We can do the business over the internet globally.

Disadvantages of Wide Area Network:-

Security issue: A WAN network has more security issues as compared to LAN and MAN network as all the technologies are combined together that creates the security problem.
Needs Firewall & antivirus software: The data is transferred on the internet which can be changed or hacked by the hackers, so the firewall needs to be used. Some people can inject the virus in our system so antivirus is needed to protect from such a virus.
High Setup cost: An installation cost of the WAN network is high as it involves the purchasing of routers, switches.
Troubleshooting problems: It covers a large area so fixing the problem is difficult.

Thank you!!!!

FIRSTBEGIN

COMPUTER NETWORK BASICS