NETWORKS

Computer network

A computer network is a group of computer systems and other computing hardware devices that are linked together through communication channels to facilitate communication and resource-sharing among a wide range of users. Networks are commonly categorized based on their characteristics.

HistoryA computer network, or simply a network, is a collection of computers and

other hardware components interconnected by communication channels that

allow sharing of resources and information. Today, computer networks are

the core of modern communication. All modern aspects of the 

public switched telephone network (PSTN) are computer-controlled.

Telephony increasingly runs over the Internet Protocol, although not

necessarily the public Internet. The scope of communication has increased

significantly in the past decade. This boom in communications would not

have been possible without the progressively advancing computer network.

Computer networks, and the technologies that make communication between

networked computers possible, continue to drive computer hardware,

software, and peripherals industries.

Types of network• There are several different types of computer networks. Computer

networks can be characterized by their size as well as their purpose. The

size of a network can be expressed by the geographic area they occupy

and the number of computers that are part of the network. Networks

can cover anything from a handful of devices within a single room to

millions of devices spread across the entire globe.

• Some of the different networks based on size are:

Personal area network, or PAN

Local area network, or LAN

Metropolitan area network, or MAN

Wide area network, or WAN

Personal Area NetworkA Personal Area Network or simply PAN, is smallest network which is

very personal to a user. This may include Bluetooth enabled devices or

infra-red enabled devices. PAN has connectivity range up to 10 meters.

PAN may include wireless computer keyboard and mouse, Bluetooth

enabled headphones, wireless printers and TV remotes for example.

Local Area Network

• A computer network spanned inside a building and operated under single

administrative system is generally termed as Local Area Network. Usually,

Local Area Network covers an organization’s offices, schools,

college/universities etc. Number of systems may vary from as least as two to as

much as 16 million

• LAN provides a useful way of sharing resources between end users. Resources

like Printers, File Servers, Scanners and internet is easy sharable among

computers.

• Local Area Networks are composed of inexpensive networking and routing

equipment. It may contains local servers serving file storage and other locally

shared applications. It mostly operates on private IP addresses and generally do

not involve heavy routing. LAN works under its own local domain and controlled

centrally. LAN uses either Ethernet or Token-ring technology. Ethernet is most

widely employed LAN technology and uses Star topology while Token-ring is

rarely seen. LAN can be wired or wireless or in both forms at once.

Metropolitan Area Network

• MAN, generally expands throughout a city such as cable TV network. It can be in form of Ethernet, Token-ring, ATM or FDDI.

• Metro Ethernet is a service which is provided by ISPs. This service enables its users to expand their Local Area Networks. For example, MAN can help an organization to connect all of its offices in a City.

• Backbone of MAN is high-capacity and high-speed fiber optics. MAN is works in between Local Area Network and Wide Area Network. MAN provides uplink for LANs to WANs or Internet.

Wide Area Network

• As name suggests, this network covers a wide area which may span across

provinces and even a whole country. Generally, telecommunication networks

are Wide Area Network. These networks provides connectivity to MANs and

LANs. Equipped with very high speed backbone, WAN uses very expensive

network equipment.

• To cover a great distance WAN’s may transmit data over leased high-speed

phone lines or wireless links such as Satellite.

• WAN may use advanced technologies like Asynchronous Transfer Mode

(ATM), Frame Relay and SONET. WAN may be managed under by

more than one administration.

BENEFITS OF NETWORK

• benefits of networking

• There are lots of advantages from build up a network, but the three big facts are:-

• File Sharing …….

• From sharing files you can view, modify, and copy files stored on a different computer on the network just as easily as if they were stored on your computer.

BENEFITS OF NETWORK

• Resource Sharing ………

• Resources such as printers, fax machines, Storage Devices (HDD, FDD and CD Drives), Webcam, Scanners, Modem and many more devices can be shared.

• Program Sharing ………

• Just as you can share files on a network, you can often also share program on a network. For example, if you have the right type of software license, you can have a shared copy of Microsoft Office, or some other program, and keep it on the network server, from where it is also run

THE END