bandwidth is the number of gigabytes of data that your website is allocated to transfer from the web hosting server to your users in one month. This number is not an absolute, it's just the number of gigabytes of bandwidth you pay for in the monthly price of your hosting plan.If your users are so many or your website is so busy that you go over your bandwidth allotment in a month, then you are charged extra for each gigabyte over the amount included in your hosting plan.