Bandwidth is basically the amount of data, which flows through a network wire in a specific timeframe. For a lot of web hosting providers, this timeframe is usually a month. Typically, web hosting providers are being charged a specific amount monthly or annually for a given amount of bandwidth coming from the wholesale data centers and backbone providers. This cost is passed on to online consumers in web hosting plans.
With the very wide variation in the web hosting companies in the market, it could sometimes be hard to be able to assess exactly how much bandwidth your website needs. Exactly how much is a gigabyte of bandwidth? To better understand it, let us try to put it in perspective. If you website is on the average and has a size of more or less 50 kilobytes, if you have a gigabyte for your bandwidth, then your website could be visited and viewed 20,000 times. This would be more than enough for the average website which is used for a hobby. And if a visitor would view around 4 pages from your website monthly, your website could still be viewed 5,000 times every month.
You could determine how much your bandwidth needs are by having a good idea of what exactly you are planning to do with your web hosting account. If you think you would need to serve a hefty number of multimedia like video and music, as well as large amounts of pages, which are powered by flash, then you might need to get a dedicated server. If you do not have an exact idea of how much bandwidth you would need and if you have a limited budget and have a website which is just starting out, you could probably choose the company which would be able to offer you the most at a reasonable price.