Concepts such as Local Area Networks, Wide Area Networks, and servers
were generally foreign to anyone except systems managers and network administrators.
But with the development of the Information Superhighway and the proliferation
of the Internet, anyone with on-line connectivity is engaged in a network
relationship of one kind or another. Whether you're chatting on America
Online, picking up free e-mail from Juno, or telecommuting from home, you're
A computer network is a collection of hardware including computers,
terminals and connecting devices that utilize communications channels to
share information, hardware and software.
Networks that cover a limited geographic area, such as an office building
or a school, are called Local Area Networks, or LANs. LAN systems are usually
hard-wired together or may utilize phone lines for their connectivity.
Wide Area Networks, or WANs, in contrast, are more global in nature
and use a combination of phone lines, satellites and microwaves as communication
channels. The Internet is by far the largest and best-known example of
At the heart of all networks is the client-server relationship. The
server is a program which provides a service to other programs, called
clients. Server programs usually reside on a dedicated computer that is
often referred to as "the server." Each PC or terminal that connects to
the server has the corresponding client software necessary to make the
The computer client-server relationship is not unlike the relationship
between a customer and a restaurant food-server. A customer enters the
restaurant, sits at a table and peruses the menu. Once a decision is made,
the customer gives the request to a food server who then completes the
necessary tasks required to deliver the entree to the customer -- hopefully
in a reasonable period of time.
At the Internet restaurant, however, you never have to leave the comfort
of your home or office when ordering from the vast cybermenu. As a customer,
you make your on-line connection and once linked, your orders are delivered
to thousands of servers around the world, anxious to fulfill your requests.
Servers and clients have a proscribed set of rules or protocols that
are built into their respective programs. Web servers on the Internet utilize
Hypertext Transfer Protocol (HTTP) for information exchange and software
applications such as Netscape and Explorer are the client applications
that support HTTP and allow you to view documents on the World Wide Web.
To transfer or download files from the Internet, you must have an FTP
client, or software that supports File Transfer Protocol and e-mail as
well as its own protocols. Usually, client software for Internet connectivity
is bundled together in applications such as Netscape, Explorer, America
Online and CompuServe to enable Web browsing, e-mail and file transfers
all from one program.
The Eudora e-mail and CUTE FTP clients are examples of stand-alone programs
that can be used with your Internet connection, independent of applications
such as Netscape. Microsoft Exchange is another example of client software
that Windows 95 users will recognize by the inbox icon that's installed
by default on the 95 desktop. This is an e-mail and messaging client, but
it requires an outbox as well -- a network server connection on the other
end to enable the flow of electronic messaging.
Small businesses running on a LAN often believe, mistakenly, that they
can exchange inter-office e-mail utilizing the default Exchange client.
What's missing here is the Exchange server counterpart. This software is
not included with Windows 95 and the licenses must be purchased separately.
Additionally, one of the PC's on the network must be designated as the
mailbox or mail server to process the office messages.
For the sharing and exchange of information on a network, both sides
of the client-server equation must be in place. Server software must be
installed on a computer dedicated to processing the demands of other computers
on the network and client software allows individual PCs to communicate
with the server and make requests for information and resources.
Understanding this client server relationship will empower the user
with the tools to troubleshoot problem areas and gain maximum benefit from
the biggest network of all -- the Internet.
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