computer network

computer network introduction:

A collection of computers and other devices together via communication devices and communication channels for sharing information and other resources is called a computer network.

computer network explanation:

The resources may include scanners, hard disks, and printers, etc. The computers on a network can be connected through cables, telephone, lines, radio waves, satellites, or infrared light beams. A computer network is also known as an information network or simply net

In a computer network, a network operating system is used that enables the connected computers to communicate with each other. The network operating system controls and coordinates the activities of computers that are connected to the network.

computer network Examples:

1.windows NT
2.UNIX
3.Novell

COMPUTER NETWORK WITHOUT CABLES:

server computer:

A computer in the network that controls the overall functioning of a network is called a server computer it is also known as a central computer or host computer.

computer network Terminals or nodes:

The devices other than the server computers within the network are called terminals. Terminals are also known as nodes.

COMPUTER NETWORK BENEFITS:

computer networks have many advantages or benefits. The main advantages are as follows:

1. Communication:

using a different network, multiple people can communicate with each other all over the world. People can communicate at a very low cost via e-mail, chatting, telephone, video telephone, video conferencing, groupware, blogs, wikis, and SMS services, etc.

2. Data Sharing:

data or information can be shared among different authorized users. Any authorized user can access data stored on other computers on a network.

3.  Sharing Resources:

In a computer network, resources such as printers, plotters, scanners, CD-ROM, drives, modems, and hard disks can be shared among different users.

4.Centralized Software Management:

All of the software is installed or updated on one computer(the file server). This saves time for installing or updating individual computers throughout the building. Users connected to a network can access these software/or program.

5.Saving Money:

An organization can save a lot of money by sharing different devices such as printers, plotters, scanners, and large hard disks over a network. without a facility of the network, These devices have to be arranged separately for each user.it becomes very costly for an organization. Similarly, different software can be shared over a network instead of purchasing a separate copy of the software for each user.

6.Data Security and Management:

The computer network provides centralized data storage. Data can easily be managed.it becomes easier for the network administrator for taking backup of data. Similarly, security features can be implemented easily.

7.Saving Disk Space:

In a computer network, all computers use the same copy of application programs and data files. These are only stored on a hard disk of the server computer. There is no need to store application programs and data files on individual computers on the network. In this way, disk space on each computer is saved.

8.Saving Time and Efforts:

A lot of time and effort is saved when only one copy of application programs and data files is saved on a server computer. IT is because: installing application programs and data files in all client computers on a network requires more time and effort.

9.Remote Access:

A network also provides the facility of remote access. A user can access the network from anywhere in the world by connecting its remote terminal to the network. For example, an employee of an organization can work at home by connecting its computer or terminal to the computer network at the office.

Computer Network Disadvantages: 

Computer networks also have some disadvantages. The main disadvantages are as following:

1.Network is expensive to install. Cables, network cards, and software are expensive, and the installation requires the services of a technician. Proper maintenance of a network is also required.

2.When any fault occurs in a file server, the entire network may fault. The users cannot access any data or application.

3.When a cable is broken(or any other fault occurs in a cable), the entire network may fault.

4.Network faults could lead to loss of data.

5.User work is dependent upon the network.

6.System is opened to hackers

7.Resources could be located too far from users.

Computer Network Components:

The computer network components are as following:

1.Hub:

A computer hub is a physical layer networking device that is used to connect multiple devices in a network. They are generally used to connect computers in a LAN network. A hub has many ports in it. A computer that intends to be connected to the network is plugged into one of these ports.

 2.Switch:

A switch is a device in a computer that connects other devices together. different data cables are plugged into a switch to enable communication between different network devices.

3.NIC:

 A network interface card (NIC) is a hardware component, which is installed on a computer that can connect to a network. Modern NICs provide the functionality to computers such as support for input or output devices, direct memory access, data transmission, network traffic, and partitioning.

4.Server:

A computer network in which a centralized, powerful computer called the server

A network server is a powerful computer that provides shared resources to workstations and other servers on a network. The shared resources can include, email server, hardware access, and, disk space.

5.Client:

 A client is a computer that connects the resources of a remote computer, or server. Many corporate networks comprise a client computer for each employee, each of which connects to the desired server. The server provides resources like information, files, Internet and intranet access, and external processing power. In the case of processing, any work done on the server is said to as "server-side". Any work done on the local client is said to be as  "client-side."

6.Router:

A router is a network of devices that forward data between computer networks. Routers perform the traffic directing functions. Data sent through the internet, which is a web page or email is in the form of data packets. A packet is typically transferred from one router to another router through the networks.

7.Modem:

A modem is a hardware device that converts data from a digital format for communication directly between devices with specialized wiring through transmission media such as radio or telephone lines. A modem modulates one or more signals to encode digital information for transmission. The aim is to produce a signal that can be transmitted easily and decoded easily to reproduce the original digital data.