Computer Network
A computer network is a
group of computers connected to each other electronically. This means
that the computers can "talk" to each other and that every computer
in the network can send information to the others. Usually, this means that the
speed of the connection is fast - faster than a normal connection to the
Internet. Some basic types of computer networks include:
·
A local
area network (often called a LAN) connects two or more computers, and may
be called a corporate network in an office or business setting.
·
An
"Internetwork", sometimes called a Wide Area Network (because
of the wide distance between networks) connects two or more
smaller networks together. The largest internetwork is called the Internet.
Computers can be part of several different networks. Networks
can also be parts of bigger networks. The local area network in
a small business is usually connected to thecorporate network of
the larger company. Any connected machine at any level of the organization may
be able
to access the Internet, for example to demonstrate computers in the
store, display its catalogue through a web
server, or convert received orders into shipping instructions.
Microsoft Windows, Linux and most
other operating systems use TCP/IP for networking. Apple
Macintosh computers used Appletalk in the past, but it uses TCP/IP now.
To set up a network an appropriate media is required. This can
be wired or wireless. Twisted-pair, co-axial or fiber-optic are examples of
cable and infra-red, blue-tooth, radio-wave, micro-wave etc. are wireless media
used for networking. When you are working with a mere LAN, computers, media and
peripherals are sufficient. But when you are working with a wider range you
have use some additional devices like bridge, gateway or router to connect
different small or large networks. And obviously a protocol must be maintained.
To set up a network you have to select an appropriate topology
to arrange the hardware devices using the media. Topologies generally used are
bus-topology, ring-topology, star-topology, tree-topology, object-oriented
topology etc. Among these star-topology and tree-topology are most popular
nowadays.
