Bandwidth can be a confusing concept to those that are new to the internet or unfamiliar with some of what goes on behind the scenes. This article is designed to give you a basic understanding of what bandwidth is and how it might apply to web sites and internet usage.

Dictionary.com defines bandwidth as "the transmission capacity of an electronic communications device or system; the speed of data transfer". While that is quite accurate, it is not necessarily easy to understand.

Explanation & Real-World Analogy

Bandwidth is essentially the speed of a connection, or the amount of data that flows from a site's server out to the viewer at any given time. When someone visits a site, the various parts that make up the page are sent (transferred) to the viewer so that they can read or interact with the page.  This means that all of the parts that make up a page (HTML code, images, JavaScript, CSS, etc.) all must be sent, and will all generate a certain amount of traffic.

Imagine your internet connection as the plumbing in your home, and the web page you are trying to view like a bucket that gets filled with water (the parts and pieces that make up the page). You can't do anything with the bucket until it's full, so you just have to sit and wait. The wider the pipes in your home are, the more water can flow through them into the bucket, and the faster you will be able to do something with it. If the pipes are very wide, you will get a lot of of water all at once, where as if they are narrow, you will only get a little at a time, which will make for a much longer wait.

In other words, bandwidth is the width of the band (pipe, stream, etc) across or through which information flows.

Bandwidth Usage

Most people, especially those that own or host their own web site, are concerned with bandwidth usage. This is the amount of information that is transferred during a fixed period of time, often a month. Most hosting companies impose a bandwidth usage maximum in order to avoid bogging their connections down such that everything slows to a crawl.

Going back to the plumbing analogy, your bandwidth usage is very much like your monthly water usage, although in your home, you are charged per unit of water, while in the context of the internet, you are charged or penalized if you go over your limit. Imagine that you have friends over for a party, that they are all very thirsty, and that you want to serve as many as possible as quickly as possible. If your spouse is upstairs taking a shower, you will have less water immediately available to serve your guests. It will flow slower, because your pipes may not be wide enough to allow full water pressure upstairs and in your kitchen. This is exactly like using bandwidth (or diverting water upstairs while someone in the kitchen is trying to fill a lot of glasses).

On the internet, the more people are surfing the web through the same connection, the slower the information will flow. If someone is downloading tons of MP3s all at once at the same time as you are trying to read your email, the pipes will be full of their MP3 data, leaving very little room for your email data, which will make the process very slow for you. The good news is that most internet service providers have very high bandwidth (extremely wide pipes) such that all that MP3 data doesn't come anywhere near filling the pipes and it flows to its destination.

Bandwidth & Web Sites

Think of web pages as public water fountains set up along a street. Each of these fountains has a different flavor, so people want to visit many of them, some being more popular than others. If there are a lot of people drinking at one fountain (there are lots of spouts), the water pressure at other fountains will be very low. It is for this reason that the plumbing company for that street (the web host) limits the amount of water (information) that is allowed to flow through one fountain.

It is very important to consider your maximum monthly bandwidth when considering a web host. If you have a small site and you expect very little traffic, it is safe to take a cheap hosting plan with a low bandwidth limit. If you are starting an e-commerce site with thousands of pages and expect it to become immensely popular (or hope it will), then you should consider paying a bit more each month for a plan that provides a higher monthly bandwidth limit. You can always start with a smaller plan, but make sure that you can upgrade in the middle of the month with no penalties in case you start approaching your bandwidth limit. There is always a risk that your web host will suspend your account if you reach your limit, causing an embarrassing "bandwidth exceeded" page to be displayed to visitors of your site instead of the normal content.

Additional Links & Resources

The following links and resources will provide you with more information on bandwidth and bandwidth usage.

• Wikipedia entry for "bandwidth"
• Wikipedia entry for "bandwidth hogging"
• Bandwidth Explained
• About.com - Definition of Bandwidth

Copyright Information

This article was written by Jerome Dane at Blank Canvas Productions, LLC and may not be reproduced in whole or in part without written permission from the author. It's source can be found here.