In general, any outward bound traffic from a web site is considered to be data transfer. Every time a person visits your website every web page, image, midi file, mp3, pdf, quicktime video and other related files are viewed, data transfer is generated. Our web hosting packages include a generous amount of free data transfer which should be more than enough for most sites. Additional data transfer beyond the threshold of most sites can be purchased at a relatively small charge to support the increased traffic.