Bandwidth and Disk space Terms

Bandwidth and disk space are terms often ignored by people shopping for a shared web hosting. You should ask yourself, “What if my website becomes really popular overnight, and draws in thousands or millions of visitors? Will I pay hefty charge for the huge data transfer?”

Of course, most websites won’t go past their bandwidth quota by high traffic alone, but if you provide some files for downloads in your website, it can potentially happen.

From: http://www.hongkiat.com/blog/web-hosting-consumer-guide-9-tips-you-should-know/