Files that are loaded to or from servers uses internet bandwidth to push files along the network at various speeds. Every time you upload a file to your ISP, surf the web or use an audio application, you are using bandwidth.  

Bandwidth measures the volume of data transmitted over an internet connection. You have to know how much bandwidth you need while choosing hosting plans. 

Bandwidth is a bunch of wires or fibres connecting servers to a network. Depending on the grade of the wire it determines how much data is coming across the network where your web-site is hosted. When someone attempts to get more data than can be handled by the network, the whole network slows down. 

Be careful when someone claims they provide unlimited bandwidth or monthly transfer. Anyone claiming "Unlimited Bandwidth" is simply lying. There's no such thing as "Unlimited Bandwidth". 

ISP’s can put a limitation on bandwidth at certain times during peak periods or charge you a flat fee per month for bandwidth usage. If you go over the flat fee, then they charge you extra for using extra bandwidth.  

Some ISP’s will shut down the transmissions until traffic is more stable on the network. Most of the time, high bandwidth sites on these "Unlimited" plans will be disconnected, and no refund given. Normally, the web hosting company will say that the site violated its Acceptable Use Policy or Terms of Service. 

Whenever you visit a site promoting "Unlimited Bandwidth" as one of the account features, be sure to visit the Acceptable Use Policy, or the Terms of Service. Read the fine text about the so-called "Unlimited" disclaimer.  

When you first look for web hosting services (those who state clearly bandwidth offered), you have to make your best estimation and watch your usage carefully in the first few months. 

You can load most files (images, sound files, videos and flash scripts and other programs) in your web site. This excludes, of course, banners and pop ups and specific documents and images which are supposed to be loaded from a central server.  

Large audio/video files, computer programs, and file downloads require more bandwidth. Flash web sites use tons of bandwidth. Virtual Reality (VR) and full-length three-dimensional audio/visual presentations require the most bandwidth of all. 

Bandwidth bandits link to images and other files directly to some other server instead of putting them on their local server. There are various reasons as to why they do this but one reason is to get as much bandwidth as possible to show their links and images. So, they “steal” images or audio files each time the site is initialized meaning that they steal the bandwidth.  

There are certain ways that you can stop the person from stealing your bandwidth allocation. If they have an email, I would contact them personally or go through Network Solutions and do an IP lookup which will give you information on the person and who the site is registered to. You can always get in touch with the company that hosts their site too. 

Bandwidth can be expensive and the last thing that you want is someone stealing it.