When you want to add multimedia to your site, there are two decisions you have to make. You have to decide which format to use for the data, and how you plan to integrate the multimedia features with the rest of your content. Before discussing the multitude of formats available, I'll talk about how to present multimedia files. The two options there are linking and embedding. When you link to a multimedia file, it's up to the browser (and user preference) to determine how best to handle it. If the browser can handle the data itself or the user has installed a plug-in compatible with the file type, sometimes the media will play within the browser window. If the browser has no idea how to handle the file, it will generally offer to let you download the file. In other cases, the browser will launch an external application like Windows Media Player or RealPlayer to handle the file. The other option is to embed the media within a page. In that case, you include tags in your page that indicate how the media should be presented within that page. The upside of this approach is that it enables you to seamlessly integrate multimedia into a website. The downside is that if your user doesn't have the right software, the experience won't turn out to be seamless. They'll see a broken file, be prompted to download additional software, or otherwise be distracted from what they were trying to accomplish. The key when embedding multimedia files is to make sure that this happens to as few users as possible.