Traffic, bandwidth, data transfer refers to the amount of information transmitted from and to your site for your visitors. The factors that influence the use of traffic are:
1. The traffic we receive ( visitors to your site)
2. The size of the site
3. The type of files offered on the site.
For example, if your site has 1 MB including pages and images, and 100 people visit your site, accessing all the pages, the traffic generated will be about 100 MB.