Transfer refers to the amount of data you can transfer to and from your hosting account / server. In the web hosting industry, the word "bandwidth" is also used to describe transfer. Data transfer is measured anytime a file is uploaded/downloaded to/from your account.
Every time that file is downloaded/uploaded, the equivalent of the space it takes is subtracted from your remaining transfer. If a file downloaded from your website is 5 MB in size, then 5 MB of transfer will be deducted from your monthly allowance.
If you finish the monthly data transfer allow for your package, then you'll see "Bandwidth limit exceeded" message untill the beginig of next month. (Your Data Transfer reset to zero on the beginig of every month), Also you can upgrade your account to higher Data transfer package
