The Basic Concept of Networking
The idea of networking has been around for a long time and has
taken on many meanings. If you were to look up "network" in your
dictionary, you might find any of the following definitions:
- An openwork fabric; netting
- A system of interlacing lines, tracks, or channels
- Any interconnected system; for example, a
television-broadcasting network
- A system in which a number of independent computers are
linked together to share data and peripherals, such as hard
disks and printers
Obviously, the last definition is the one we are concerned with
in this instance. The key word in the definition is "share." Sharing
is the purpose of computer networking. The ability to share
information efficiently is what gives computer networking its power
and its appeal. And when it comes to sharing information, human
beings are in many ways similar to computers. Just as computers are
little more than collections of the information they have been
given, so we are, in large part, collections of our experiences and
the information given to us. When we want to expand our knowledge,
we broaden our experience and gather more information. For example,
to learn more about computers, we might talk informally with friends
in the computer industry, go back to school and take a class, or
work through a self-paced training course. Whichever options we
choose, when we seek to share the knowledge and experiences of
others, we are networking.
Another way to think of networking is to envision a network as a
team. This might be a sports team, such as a football team, or a
project team. Through the efforts of all involved -the sharing of
time, talent, and resources-a goal is accomplished or a project is
completed. Similarly, managing a computer network is not unlike
managing a team of people. Sharing and communicating can be simple
and easy (a quarterback calling a play in the huddle) or complex (a
virtual project team located in different time zones around the
world that communicates through teleconferencing, e-mail, and
multimedia presentations over the Internet to complete a project).
Introducing Computer Networking
At its most elementary level, a computer network consists of two
computers connected to each other by a cable that allows them to
share data. All computer networking, no matter how sophisticated,
stems from that simple system. While the idea of connecting two
computers by a cable may not seem extraordinary, in retrospect it
has proven to be a major achievement in communications.
Computer networking arose as an answer to the need to share data
in a timely fashion. Personal computers are powerful tools that can
process and manipulate large amounts of data quickly, but they do
not allow users to share that data efficiently. Before networks,
users needed either to print out documents or copy document files to
a disk for others to edit or use them. If others made changes to the
document, there was no easy way to merge the changes. This was, and
still is, known as "working in a stand-alone environment."
Stand-alone environment
Copying files onto floppy disks and giving them to others to copy
onto their computers was sometimes referred to as the "sneakernet."
This early form of computer networking is one that many of us have
used and perhaps still use today. See the illustration below; it
might bring back some fond memories.
The sneakernet
This system works well in certain situations and has its
advantages - it allows us to stop for a cup of coffee or socialize
with a friend while we exchange and merge data - but it is far too
slow and inefficient to meet the needs and expectations of today's
computer users. The amount of data available to be shared and the
distances we want the data to travel far exceed the capabilities of
the sneakernet.
But what if the computer were to be connected to other computers?
Then, it could share data with the other computers and send
documents to the other printers. This connecting together of
computers and other devices is called a network, and the
concept of connected computers sharing resources is called
networking.
A simple computer network
Why Use a Computer Network?
With the availability and power of today's personal computers,
you might ask why networks are needed. From the earliest networks to
today's high-powered personal computers, the answer has remained the
same: networks increase efficiency and reduce costs. Computer
networks achieve these goals in three primary ways:
- Sharing information (or data)
- Sharing hardware and software
- Centralizing administration and support
More specifically, computers that are part of a network can
share:
- Documents (memos, spreadsheets, invoices, and so on).
- E-mail messages.
- Word-processing software.
- Project-tracking software.
- Illustrations, photographs, videos, and audio files.
- Live audio and video broadcasts.
- Printers.
- Fax machines.
- Modems.
- CD-ROM drives and other removable drives, such as Zip and
Jaz drives.
- Hard drives.
And more sharing options exist. The capabilities of networks are
constantly expanding as new ways are found to share and communicate
by means of computers.
Sharing Information (or Data)
The ability to share information quickly and inexpensively has
proven to be one of the most popular uses of networking technology.
It has been reported that e-mail is by far the number-one activity
of people who use the Internet. Many businesses have invested in
networks specifically to take advantage of network-based e-mail and
scheduling programs.
By making information available for sharing, networks can reduce
the need for paper communication, increase efficiency, and make
nearly any type of data available simultaneously to every user who
needs it. Managers can use these utilities to communicate quickly
and effectively with large numbers of people and to organize and
schedule meetings with people drawn from an entire company or
business enterprise far more easily than was previously possible.
Scheduling a meeting with Microsoft Outlook
Sharing Hardware and Software
Before the advent of networks, computer users needed their own
printers, plotters, and other peripherals; the only way users could
share a printer was to take turns sitting at the computer connected
to the printer. The illustration below shows a typical stand-alone
workstation with a printer.
A printer in a stand-alone environment
Networks make it possible for several people to share data and
peripherals simultaneously. If many people need to use a printer,
they can all use the printer available on the network. The
illustration below shows a typical network environment in which five
workstations share a single printer.
Sharing a printer in a networking environment
Networks can be used to share and standardize applications, such
as word processors, spreadsheets, inventory databases, and so on, to
ensure that everyone on the network is using the same applications
and the same versions of those applications. This allows documents
to be shared easily and creates training efficiencies: it is easier
for people to master one word processing application thoroughly than
to try to learn four or five different word processing applications.
Centralizing Administration and Support
Networking computers can simplify support tasks as well. It is
far more efficient for technical personnel to support one version of
one operating system or application and to set up all computers in
the same manner than to support many individual and unique systems
and setups.
The Two Major Types of Networks: LANs and WANs
Computer networks are classified into one of two groups,
depending on their size and function. A local area network
(LAN) is the basic building block of any computer network. A LAN
can range from simple (two computers connected by a cable) to
complex (hundreds of connected computers and peripherals throughout
a major corporation). The distinguishing feature of a LAN is
that it is confined to a limited geographic area.
A local area network (LAN)
A wide area network (WAN), on the other hand, has no
geographical limit. It can connect computers and other devices on
opposite sides of the world. A WAN is made up of a number of
interconnected LANs. Perhaps the ultimate WAN is the Internet.
A wide area network (WAN)
