HARTRON EXAM THEORY PART -12 Computer Network

Computer Network

When the computer first appeared, it was a stand-alone device. Later, its wide use opened the way for loving hardware and software through which computers could communicate with each other. Computer application means the process through which data instructions and information from one computer to another computer reach Rohtak. Initially, only large computers had the capability of communication But now even the smallest computers and devices can communicate with each other.

Network

A network is a group of computers and devices that are connected through a communication channel. Through this, the user can share data information hardware and software with other users. Personal and institutional computers are combined into one network for several reasons. Who has the ability to share data, information, hardware and software and establish communication.

Need networking

To share hardware:

Each computer in a network can access and use hardware. For example, suppose a network consists of many computers and each computer requires a laser printer. In such a situation, every computer with the same laser printer connected to the network can be used.

To share data and information:

While working on any computer in a network, any legitimate user can access and use the data and information stored on any other computer. For example, the database of computer information is saved on the hard disk of the server. Any legitimate user in the network, even a mobile user using a handheld computer, can access this database and use it.Access to storage data and information and use them is a very important feature of many networks.

To share software:

The software which is used extensively in software sharing is stored in the hard disk of the server so that multiple users in the network can reach and use them simultaneously. When you purchase the network version of a software package, the software vendor issues a legal agreement to you Called a site license. This allows multiple users to use the software package simultaneously. Site license fees are usually determined by the number of computers or users involved in the network. Compared to purchasing separate software for each computer, the cost of sharing them through the network is almost negligible.

Facilitated Communication:

Using the network, people can communicate in an effective and easy manner via email, instant messages, chat rooms, telephony, and vodicoconferencing. Email messages are usually prompt delivery. Sometimes this communication is also used in a business network.There is a full range of network sizes. If a small network connects 2 computers, then millions of computers in the world are connected in a global network such as the Internet. The network connects all types of computers whether it is a headheld computer or a supercomputer.

Types of network

There are mainly three types of networks. LAN, MAN, WEN, these are used by private, business houses and institutions. Because every business and organization has its own needs, therefore every network is unique in itself.
The size of the network depends on what type of network the business house or organization wants to use. Networks of different sizes translate data differently. For example, the network of an institution with a thousand users is organized differently and needs a diversity of components that do not exist in a network that has only five users.

Local area network (LAN)

A computer network in a building or group of buildings in which two or more computers are physically connected to each other is called a local area network. Connected computers are called work stations. In this, the computers are connected to each other so that expensive devices such as laser printers or joint use can make the database and applications in the server available for all workstations.Local area networks have their characteristic topology such as a bus ring or star and implement more networking protocols such as Apple, Tonk, Ethernet or TCP / IP simultaneously.

Metropolitan area Network (MAN)

It is a high-speed network that can carry voice, data and messages up to 200 Mbps (mega bits per second) rapidly up to 75 kilometers in a few blocks of buildings or across the city. The transmission speed is based on the architecture of the network and may be higher for shorter distances. Man, which includes 1 or more LANs here, such as telecommunications equipment such as microwaves and satellite relay stations, is smaller than a wide area network but usually has a higher speed.

Wide area network (WAN)

Wan is a computer network that is quite different from a local area network due to its ability to communicate over long distances. This network can cover the entire country and all the sites of a large multinational company. WEN is used to connect local area networks and other networks.So that a user sitting at one place can communicate with another user sitting somewhere far away through his computer. Most vans are made by a particular organization and are private. Others are created by the Internet service provider and connect to the Internet of an organization by providing a connection to the LAN. Communications are usually provided by one or more national or international governmental units.

Network hardware

Network hardware includes devices that join a network. Network hardware is required for all networks to function.

computer:

The most important function of a network is to connect computers. People who use them can work more effectively when computers are connected. It is not necessary that all computers connected in the network are the same. For example in a network desktop computers such as IBM Compatible and Macintosh computers, or portable computers such as netbooks and personal digital assistants (PDAs).

Network Interface Card (NIC):

An expansion card or other device that provides network access to computers and other devices such as printers. The network interface plays the role of an intermediary between cards, computers and physical media such as only through which transmission occurs.

Connector:

A connector is a device that connects two networks. The most common connectors are hubs, bridges, and routers.

Cables:

A group of wires or glass wire or flexible metal. All cables are used in electronics. And fall from plastic or rubber.

Resource:

Any part of a computer system or network such as a disk drive, printer or memory that may be allocated to a program or the process that is running.

Peer to peer network

Network of 2 or more computers that use the same program or type of program for communication and data sharing. Each computer or peer is considered to have the same responsibilities and each functions in the same way as other computers in the network. Like the client / server architecture, a file server is not required here.However the network does not work as well as it does under client / server, especially during heavy loads.
The peer to peer network works best in a small environment. All computers in the network require personal administration and maintenance. If you want to connect more than 10 computers, do not use peer to peer network.

Resource:

Resources include printers and models. They are usually connected to a computer in a peer to peer network. This computer shares their use with other computers in the network.

Program:

Most software applications such as word processors and spreadsheet programs that are used in peer to peer networks are installed on each computer. Users can use them in their computers to view and work on documents prepared by other users of the network.

Performance:

If a computer uses resources, its performance may be affected. For example, if a printer in a Pier to Pier network is connected to a computer, the computer will work slower each time a user is printing a document.

Installation:

All computers in a peer to peer network must have a network operating system and all applications installed. Each computer in the network should be set up in such a way that it itself is capable of accessing information and resources badly. The user should learn how to administer his computer. There is usually no dedicated system administrator for peer to peer networks.

Access to Resources:

If a computer is not working properly in a peer to peer network, other computers will not be able to access its files and resources. However, files and resources of other computers will not be affected.

Security:

In a peer to peer network, users store files and information on their own computer. Any other user can access the files and information of another user’s computer using their computer. Therefore, information is less secure in peer to peer networks.

Cost:

When fewer computers are connected to each other through a peer-to-peer network, it costs less but as the network grows it becomes a costly deal.

Client / server network

A network in which one or more computers are designed as servers and the rest of the computers in the network are called clients that can request services from the server.

Server:

A computer that provides information to self-connected computers such as web servers, mail servers and LAN servers. When a user connects to the server, the applications, files, printers and other information are available to him.

Client:

A client is a computer system that accesses service on other computers through some kind of network.

Size:

Client / server networks are generally good for large networks and can be used with any size network. Client / server networks are easy to set up and meet most of the needs of large companies.

Capacity:

The server has more memory and is faster than client or desktop computers. They are better for completing complex tasks. Sarwar has more space to store than client computers. So that the server can store and manage all the files in the network effectively.

Services:

Sarwar is commonly used to make a particular service available to the client computers in the network. As such, the print server controls the printing of all client computers in the network. Database servers store and organize large amounts of information. Most client / server networks have an administrator. It is the job of the administrator to manage the network like data backup security monitoring is done regularly.In a client / server network, the server is usually set up in a central area to administer well.

Security:

Most companies keep the network server in a closed room. Only the cable network administrator can access this room. This allows unauthorized persons to interfere in the Sarwar. If one network server is not working properly, it may affect the entire network.

Cost:

Client / server networks require special and dedicated servers which can be quite expensive. Because the server does most of the work, the client computers in the client / server network can be less powerful and cheaper.