"Chapter Five "Network

Chapter Five
Network
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5-1 What is Network
Microcomputers are often linked together to form a network.
This linkage allows many users to access the same data. A network
is a system that allows two or more computers to communicate and
share resources with each other.
Networks can sometimes be called centralized systems as all data
flows to and from these computers. The storage system on a
network is generally quite large and designed to store software
programs and data files. Not all networks or centralized systems
have PCs connected to them; some have a combination of PCs,
Macintosh machines, dumb terminals (monitor that displays
information only), smart terminals (monitor that displays
information with formatting capabilities and has limited processing
capabilities), Unix systems, or Linux systems. You can also have
portable devices such as a tablet, PDA or cellular phone connected
to a network for easy access to information or e-mail when you are
away from the office. Mainframe computers generally store
customized software applications and large amounts of data needed
by people using the computers connected to them. In order for
people spread across different locations to have access to this data,
networks need to be set up. In the past, people who needed the
information would generally have a computer with access to and
from the network connecting to the mainframe computer;
no actual information would be stored on the computer at their site.
A trend away from this is called client/server technology. A
client/server network has PCs connected that can function on their
own as well as connect to the server to access information. In this
arena, the server stores the data and the PC houses the application
software.
5-2 Types of Network
A network can be small or large, depending on the company
or user requirements.
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LAN A network connecting a small to medium number of
computers together in a confined area is called a Local Area
Network.
WAN A network connecting computers over long distances (i.e.,
between branches or offices in different provinces or states) is
called a Wide Area Network.
MAN A network connecting computers in a metropolitan area is
called a Metropolitan Area Network.
CAN A network connecting computers in a limited area such as a
campus or military base is called a Campus Area Network.
HAN A network connecting computers in a home environment is
called a Home Area Network.
Each computer requires a network interface card (NIC) and the
appropriate cables to connect it to a dedicated computer called the
network server. The cost of setting up a network varies, depending
on the number of users and their requirements