There are three main parts to the On-Demand streaming process: The broadcaster, the Content Distribution Network (CDN), and the viewer.
The Broadcaster (you)
You are responsible for creating the content (audio or video) and making it available to your chosen CDN.
Your content can come from a device (a mixer, a microphone, a camera, etc) or from files on your PC. The content needs to be Encoded into the correct format (Windows Media, Quicktime, Flash, etc) using that formats encoder (for example, Windows Media Encoder 9). This content is made available to your CDN through an FTP folder that they provide to you.
You will also need to have an internet connection available to upload the content to that FTP folder. Having a high-speed connection is not necessary for this, although it will result in much faster upload times.
Your CDN is responsible for delivering your content effectively to your audience.
The CDN receives requests from your viewers to start a stream, and does so using a Global Matrix Array. The method for effectively delivering the content is very complex, and involves determining the optimal route through the internet to your viewer, then maintaining a steady flow of data.
The purpose of any internet broadcast is to deliver the best possible experience to your audience, and to make it as easy as possible for them to view your broadcast.
All a viewer (or listener) needs to do is click on a hyperlink in your website, or in an email, to automatically begin receiving your stream (through your CDN).
The viewer will need to have an internet connection with enough bandwidth to receive the data at the same rate you are broadcasting at, and have a player installed that is able to play the broadcast (Windows Media Player is installed on about 98% of all computers in the world).
Now that you have a basic idea of how On-Demand streaming works, we can move forward and address some of the specific questions you may still have.