What is Bandwidth and Data Transfer?

Simply put, bandwidth and data transfer are synonomous, referring to the amount of data sent to and from visitors and your website. It is calculated by the size of your web page and includes all scripting and images on a page. For example, if you have a page totalling 20KB in file size, then when a visitor loads that page on their browser, they are receiving 20KB of data.

This means to calculate bandwidth, you need to consider
a) the size of your pages (or website)
b) the number of visitors to your website
c) the kind of files you offer your visitors.

Most personal websites have only a small amount of data transfer, as their websites are small in file size and they do not have a lot of visitors. Business and professional sites are larger with more visitors and therefore use more data transfer. Breal's entire site is under 2 MB in file size. Some sites may be significantly larger, especially if
they offer many graphics, audio, video or download files.

Using Breal as an example, if 1,000 visitors viewed every page on the site, the total data transfer would be 2 GB
(1,000 x 2 MB = 2,000 MB) or a single 10 KB file could be viewed 200,000 times and the data transfer would be 2 GB.
Most professional level websites will use less than 2 GB bandwidth per month.

Why do some companies charge for bandwidth and data transfer, while others claim you can have unlimited bandwith
and data transfer?

Strangely enough, free on the Internet often means fee. Look closely at many of the unlimited offers and you will
discover that there is a limit to bandwidth. You may need to contact the company and ask them to define what they mean by
'unlimited'.