Your hosting account uses bandwidth when it sends or receives data with the rest of the Internet. For example, if your hosting account contains a 1MB picture, and 2,000 visitors view the picture, it uses 2,000MB (2GB) of bandwidth.
You can check how much bandwidth your account has used, as well as its monthly limit, at any time.
In the Resource Usage section on the right, your Traffic limit and usage display.
If you want to change your hosting account's bandwidth limit, see Upgrading or Downgrading Your Hosting Account.