Bandwidth is a term that has several different meanings depending on the context. When talking about bandwidth in terms of Web Hosting it refers to the amount of data that transfers into and out of your web hosting account. Incoming data can include requests for web pages, email, FTP requests, and FTP uploads, while outgoing data includes file transfers, web pages, and email. Each hosting account is allocated a certain amount of bandwidth per month. Common figures for bandwidth range from 3 GB for small personal sites up to 200 GB for large business systems.
  

How much bandwidth do you need? This depends on the amount of traffic your website receives as well as the content. Web pages made up of text and a few pictures are very small in size but if you get thousands of visitors each day you may need a lot of bandwidth. On the other hand website content consisting of downloadable files such as software, music or video is much larger in size, so even if your traffic is fairly low you may need extra bandwidth.
   

The best way to calculate the amount of bandwidth you need is to calculate the size of your downloadable content and multiply by the number of visitors you receive each month. Add to that the number of emails sent and received and other content such as FTP uploads. The figure you come up with should be pretty accurate because it is unlikely that every visitor to your site is going to download every file or view every page. This will give you a bit of margin to play with.
   

As your web site grows and as you receive more traffic you may have to increase your bandwidth allotment accordingly. It is better to plan ahead and arrange with your web host for a larger hosting package rather than wait until you go over your limit. Check with your host to see what their policy is in regards to exceeding your bandwidth. Some will allow you to go over by a certain amount while others will shut down your site and demand that you upgrade your account before resuming service. It is always best to keep track of how much bandwidth you are using and anticipate when you need to upgrade.
    

If you feel that you have sufficient bandwidth for your website and would prefer not to upgrade you may be able to ‘throttle’ traffic if you are approaching your monthly limit. Some hosts offer this service as a way to limit incoming requests or to exclude requests once a certain number has been reached. 
   

There are several throttling options. You can limit the number of incoming requests by specifying an idle time between requests. This causes incoming requests to be delayed by a specified amount of time if too many are arriving at once. Other options are to impose a limit on data transfer within a certain time period or to limit the number of requests for a certain file. The speed of transfers can also be capped at a certain level. Throttling may not be a good idea if you depend on web traffic for your business. If your pages are slow to load or if users can’t access files they are looking for they may give up and move on to another site. If you have a lot of free content, though, throttling can be useful for keeping your hosting budget within a certain amount.