Definition: A local area network

(LAN) supplies networking capability to a group of computers in close proximity to each other such as in an office building, a school, or a home. A LAN is useful for sharing resources like files, printers, games or other applications. A LAN in turn often connects to other LANs, and to the Internet or other WAN.

A computer network is a collection of interlinked computer and / or devices through a communication medium. As per geographical area networks can be classified into three types , namely Local Area Network(LAN) ,Metropolitan Area Network(MAN) and Wide Area Network(WAN).

TYPES OF

NETWORK

LAN MAN WAN

Lan is a localised network. This type of network is useful when you want to connect two different departments in a building. The data transfer rate for LAN technologies is upto 10 GB/s . Local Area Network is a high – speed and fault – tolerant data network . High transmission rates are possible in LAN because of short distances between data network .

The following are the characteristics and purpose LAN :

LAN helps in resource sharing for example , data , software , and hardware.

LAN transfers data at a high speed.

LAN’s reach is limited .

LAN technology is generally less expensive than MAN and WAN

Networking BasicsHere are some of the fundamental parts of a network:

Network - A network is a group of computers connected together in a way that allows information to

be exchanged between the computers.

Node - A node is anything that is connected to the network. While a node is typically a computer, it

can also be something like a printer or CD-ROM tower.

Segment - A segment is any portion of a network that is separated, by a switch, bridge or router,

from other parts of the network.

Backbone - The backbone is the main cabling of a network that all of the segments connect to.

Typically, the backbone is capable of carrying more information than the individual segments. For

example, each segment may have a transfer rate of 10 Mbps (megabits per second), while the

backbone may operate at 100 Mbps.

Topology - Topology is the way that each node is physically connected to the network (more on

this in the next section).

Local Area Network (LAN) - A LAN is a network of computers that are in the same general physical

location, usually within a building or a campus. If the computers are far apart (such as across town

or in different cities), then a Wide Area Network (WAN) is typically used.

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A wireless LAN (or WLAN, for wireless local area network, sometimes referred

to as LAWN, for local area wireless network) is one in which a mobile user can

connect to a local area network (LAN) through a wireless(radio) connection.

The IEEE 802.11 group of standards specify the technologies for wireless

LANs. 802.11 standards use the Ethernet protocol and CSMA/CA (carrier

sense multiple access with collision avoidance) for path sharing and include

an encryption method, the Wired Equivalent Privacy algorithm.

High-bandwidth allocation for wireless will make possible a relatively low-cost

wiring of classrooms in the United States. A similar frequency allocation has

been made in Europe. Hospitals and businesses are also expected to install

wireless LAN systems where existing LANs are not already in place.

Using technology from the Symbionics Networks, Ltd., a wireless LAN adapter

can be made to fit on a Personal Computer Memory Card Industry Association

(PCMCIA) card for a laptop or notebook computer.