Computer Network:-
Lets understand what is Computer Network:-
It is a collection of two or more computers, which are connected together to share information and resources. Computer network is a combination of hardware and software that allows communication between computers over a network.
The two or more computers that are connected with one another for the purpose of communicating data
electronically is termed as Computer network. Besides physically connecting computer and communication devices, a network system serves the important function of establishing a cohesive architecture that allows a variety of equipment types to transfer information in a near-seamless fashion.
You can establish a network connection using either cable or wireless media.
Every network involves hardware and software that connects the computers over the network.
Note:-
ARPANET stands for Advanced Research Projects Agency Network. It was the first network developed by Vint Cerf in 1969.
Benefits Of Network:-
Some of the benefits of network are discussed below:-
1.File Sharing:-
The networking of computer helps the users to share data files.
2.Hardware Sharing:-
Users can share devices such as printers, scanners, CD-ROM drives, hard drives etc. in a computer network.
3.Application Sharing:-
Applications can be shared over the network and this allows implementation of client/server applications.
4.User Communication:-
This allows users to communicate using email, newsgroup, video conferencing within the network.
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Types of Computer Network:-
Computer network is broadly classified into various types as follows:-
1.Local Area Network(LAN):-
Local Area Network is a small and single-site network. It connects network devices over a relatively short distance. It is a system in which computers are interconnected and the geographical area such as home, office, buildings, school may be within a building to 1Km.
On most LANs, cables are used to connect the computers. LANs are typically owned, controlled, managed by a single person or organization.
They also use certain specific connectivity technologies, primarily Ethernet and Token ring. LAN provides a sharing of peripherals in an efficient or effective way.
2.Wide Area Network(WAN):-
Wide Area Network is a geographically dispersed collection of LANs. A WAN like the Internet spans most of the world. A network device called a router connects LANs to W AN.
Like the Internet, most WANs are not owned by any one organisation's , nut rather exists under collective or distributed ownership and management. WANs use technology like ATM, Frame Relay and X.25 for connectivity.
3.Metropolitan Area Network(MAN):-
It is a data network designed for a town or city. It connects an area larger than a LAN, but smaller than a WAN.
It's main purpose is to share hardware and software resources by the various users. Cable TV network is an example of metropolitan area network. The computers in a MAN are connected using co-axial cables or fibre optic cables.
4.Personal Area Network(PAN):-
Personal Area Network refers to a small network of communications. These are used in a few limited range, which is in reachability of individual person.
Few examples of Personal area network are Bluetooth, wireless USB, Z-wave and Zig Bee.
Some Important notes related to Computer Networks:-
- Server:- Server is system that responds to request across a computer network to provide a network service. It can be run on a dedicated computer. It is one of the most powerful and typical computer.
- File Server:- It is a type of computer used on a network that provides access to files. It allows users to share programs and data over LAN network.
- Protocols:- These are the set of rules used by a network for communication. it is mainly used to connect all the computers to the network.
Network Devices:-
Let's understand what is network devices?
The network devices are required to amplify the signal to restore the original strength of signal and to provide an interface to connect multiple computers in a network. There are many types of network devices used in networking.
The devices which are used for communication between different hardware’s used in the computer network are called network devices.
These devices are also known as physical devices, networking hardware, and
computer networking devices. In a computer network, each network device plays a key role based on their functionality, and also works for different purposes at different segments.
Types of Network Devices:-
There are different types of network devices used in a computer network as follows:-
- Repeater
- Network Hub
- Gateway
- Switch
- Router
- Bridge
- Modem
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Some of them are described below:-
1.Repeater:-
Repeaters have two ports and can connect two segments of a LAN. It amplifies the signals when they are transported over a long distance so that the signal can be as strong as the original signal. A repeater boosts the signal back to its correct level.
The main function of this device is to reproduce the
signal on a similar network before the signal gets weak otherwise damaged. The significant point to be noted regarding these devices is that they do not strengthen the signal. Whenever the signal gets weak, then they reproduce it at the actual strength. A repeater is a two-port device.
2.Hub:-
Hub is a like a repeater with multiple ports used to connect the network channels. It acts as a centralised connection to several computers with the central node or server. When a hub receives a packet of data at one of its ports from one network channel, it transmits the packet to all of its ports to all other channel.
The transferring of data in a computer network can be done in the form of packets.
The network hub is one kind of networking device in a computer network, used to communicate with various network hosts and also for data transferring.
3.Gateway:-
It is an interconnecting device, which joins two different network protocols together. They are also known as protocol converters. It accepts packet formatted for one protocol and converts the formatted packet into another protocol.
The gateway is a node in a network which serves as a proxy server and a firewall system and prevents the unauthorised access.
4.Switch:-
It is small hardware device that joins multiple computers together within one LAN. It helps to reduce overall network traffic.
Whenever a data packet is obtained from the interfaces in the switch, then the data packet can be filtered & transmits to
the interface of the receiver. Due to this reason, a switch maintains a content addressable memory table to maintain system configuration as well as memory.
Switch forwards a data packet to a specific route by establishing a temporary connection between the source and the destination. There is a vast difference between a switch and a hub. A hub forwards each incoming packet(data) to all the hub ports, while a switch forwards each incoming packet to the specified recipient.
5.Router:-
Router is a hardware device which is designed to take incoming packets, analyse packets, moving and converting packets to the another network interface, dropping the packets, directing packets to the appropriate locations, etc.
6.Bridge:-
It serves a similar function as switches. A bridge filters data traffic 🚥 at a network boundary. Bridges reduce the amount of traffic on a LAN by dividing it into two segments. Traditional bridges support one network boundary, whereas switches usually offer four or more hardware ports. Switches are sometimes called multiport bridges.
A Bridge in the computer network is used to group two or more network segments.
The main function of a bridge in network architecture is to store as well as transmit frames among the various segments. Bridges use MAC (Media Access Control) hardware for transferring frames.
7.Modem:-
It stands for Modulator-Demodulator(MODEM). It is a device that converts digital signal into analog signal(modulator) at the sender's end and convert back analog signal to digital signal 📶(demodulator) at the receiver's end, in order to make communication possible via telephone lines.
A modem is the most important network device that we used in our daily life.
A Modem is always placed between a telephone line and a computer.
Read about the Communication media :-
Read about System Utilities :-
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