Network

Network

A group of computers connected in the same way to share resources is called a network.

Network requirement

1. It distributes resources such as information or processors. 
2. It provides communication of internal processes between users and processors.
3. It provides maximum performance to the network user at minimum cost.
4. It provides a centralized control for a geographically distributed system.
5. It provides compatibility between disparate devices and software.
6. It provides central management and allocation of network resources.

Use of computer network

1. Resource sharing - enables users to share hardware such as scanners and printers. It reduces the cost price by reducing the number of hardware items purchased. Makes resources available to anyone regardless of the resource on the network and the geographic location of the user. eg - Printer, Scanner.
2. Sharing of Information - Makes data stored on another user's computer accessible to the user. It keeps everyone up-to-date regarding the latest data. Here everything is kept in a single file and no copies of the file need to be made. Ex- file database, record etc.
3. Person to person communication - eg - E-mail, Video conferencing.
4. Electronic Business - Users can buy and sell goods through electronic means as per the requirement.
5. Interactive Entertainment - Playing games.

Types of network

1. LAN (Local Area Network) - Local area network is a computer network that covers local areas such as home, office or building clusters. Currently running LANs are mostly based on Ethernet IEEE80 running on 10,100 or 1000 megabytes or wi-fi technology. Commonly used media in LAN are- Coaxial cable, Twisted pair cable, Wireless.

Features of LAN - 

1. very high data transfer rate
2. relatively small geographic range
3. No need for leased telecommunication lines.
4. Only a limited number of computers can be connected.

2. WAN (Wide Area Network) - Wide area network covers a wide geographical area. This is in contrast to LAN and MAN which are limited to either one room, one building. The Internet is the largest and most famous WAN.

Features of WAN-

1. Low speed data transfer rates compared to LAN.
2. Very large geographical range.
3. Leased telecommunication lines required. 

3. MAN (Metropolitan area network) - Metropolitan area network is a high-speed network that can carry voice, data and images up to a distance of 75 km at a speed of 200 mbps or more. The transmission speed, depending on the network structure, can be even higher for short distances. A MAN can have one or more LANs. It can also include other telecommunications equipment, such as microwaves and satellite relay stations. It is smaller than WAN but works at higher speed.

Features of MAN-

1. Covers towns and cities.
2. In this, fiber optics and cable are used as medium.
3. Sending messages is fast.