Bandwidth is the total amount of data that can be sent in a given time between two computer devices. The more bandwidth that is available, the faster the access to the server will be.
Any webmaster expecting a decent amount of traffic to their site will require a web hosting package that includes a large amount of bandwidth. This is so important, especially with the growth of your online business and, ultimately your sites. If you don't have enough bandwidth, surfers will not be able to access your site as quickly, and that may turn them off which in turn, will mean they will leave your site.
To calculate your bandwidth needs, you must know how large each page on your site is, including the graphics and any script usage you may have. Then, you multiply that by the number of views you expect the site to get every month.
For example, say you have three 5k images on your page and a 2k HTML file - you would have 17k of data on that page. Multiply that by your expected page views (let's say in this case it is 1,000 per month), and you get 17 MB of data to be transferred that month for that page alone. Now calculate this for each page, and you will know approximately how much bandwidth your entire site requires.
The best way of using bandwidth efficiently is to keep the size of your html pages low. In other words, ensure your HTML programming is adequate enough to use minimal amounts of coding for the purpose you want and, that your photos and graphics are small. To reduce photo file sizes you should always use JPEG format, which can reduce files up to 5% of its original size. Make sure to use the GIF format for graphics, as opposed to TIFFs or BMPs, which are generally much larger in file size.
If you attach URLs to your IMG SRC that link to another person's images without their permission, this is known throughout the online industry as hotlinking, which costs the person you are linking the image of money and not yourself. For this reason, hotlinking, is looked upon dimly.
The unfortunate truth is that hotlinking is rife in the online industry. However, lets not let that deter you, by utilizing a file called .htaccess on your server, you can prevent other dishonest webmasters hotlinking your images.