Data Transfer
Data transfer (commonly confused with bandwidth) is the total amount of data that is transferred from your server to your website visitors. The amount of data transferred depends on what’s on each page that your visitors click on.
Web hosting companies will tell you how much data transfer they allow you each month. This figure is usually in gigabytes (GB), although some hosts will give you unlimited data transfer. How much data transfer you need depends on the size of your web pages and the number of visitors you receive.