Web casting, or http://www.vsworld.com/?loadSwf=swf/streaming.swf broadcasting over the internet, is a media file (audio-video mostly) distributed over the internet using streaming media technology. Streaming implies media played as a continuous stream and received real time by the browser (end user). Streaming technology enables a single content source to be distributed to many simultaneous viewers. http://www.vsworld.com/?loadSwf=swf/streaming.swf Streaming video bandwidth is typically calculated in gigabytes of data transferred. It is important to estimate how many viewers you can reach, for example in a http://www.vsworld.com/?loadSwf=swf/webcast.swf live webcast, given your bandwidth constraints or conversely, if you are expecting a certain audience size, what bandwidth resources you need to deploy.