What Is a Network?

A network is nothing more than two or more computers connected by a cable (or in some cases, by a wireless connection) so that they can exchange information. Of course, computers can exchange information in other ways besides networks. Most of us have used what computer nerds call the sneakernet. That’s where you copy a file to a diskette and then walk the disk over to someone
else’s computer. (The term sneakernet is typical of computer nerds’ feeble attempts at humor, and why not? As a way to transfer information, sneakernetwas pretty feeble.)


The whole problem with the sneakernet is that it’s slow — plus, it wears a trail in your carpet. One day, some penny-pinching computer geeks discovered that connecting computers together with cables was actually cheaper than replacing the carpet every six months. Thus the modern computer network
was born.

You can create a computer network by hooking all the computers in your office together with cables and installing a special network interface card (an electronic circuit card that goes inside your computer — ouch!) in each computer so you have a place to plug in the cable. Then you set up your computer’s


If you don’t want to mess with cables, you can create a wireless network instead. In a wireless network, each computer is equipped with a special wireless network adapter that has little rabbit-ear antennas. Thus, the computers can communicate with each other without the need for cables.

Computer networking has its own strange vocabulary. Fortunately, you don’t have to know every esoteric networking term. Here are a few basic buzzwords

1. to get you by: Networks are often called LANs. LAN is an acronym that stands for localarea
network. It’s the first TLA, or three-letter acronym, that you see in this
book. You don’t really need to remember it, or any of the many TLAs that
follow. In fact, the only three-letter acronym you need to remember is TLA.

2.You may guess that a four-letter acronym is called an FLA. Wrong! A fourletter
acronym is called an ETLA, which stands for extended three-letter
acronym. (After all, it just wouldn’t be right if the acronym for four-letter
acronym had only three letters.)

3. Every computer connected to the network is said to be on the network.
The technical term (which you can forget) for a computer that’s on the
network is a node.

4. When a computer is turned on and can access the network, the computer
is said to be online. When a computer can’t access the network, it’s offline.
A computer can be offline for several reasons. The computer can be
turned off, the user may have disabled the network connection, the
computer may be broken, the cable that connects it to the network can
be unplugged, or a wad of gum can be jammed into the disk drive.

5.When a computer is turned on and working properly, it’s said to be up.
When a computer is turned off, broken, or being serviced, it’s said to be
down. Turning off a computer is sometimes called taking it down. Turning
it back on is sometimes called bringing it up.


Source :
Book: "NetWorking For Dummies" by Doug Lowe