When you are delivering media online, you have to think about what visitors need to view your files and how long what they need takes to download. File size and how long it takes visitors to download on different connections should be an immediate consideration when you are working with sound and video files.
You should note that SWF files actually progressively download, so a SWF file plays as it downloads into a visitor's computer. Streaming is a slightly different concept because streaming sound or video is not saved to the browser's cache, unlike a progressively downloaded file. The catch with streaming sound and video is that when the file is finished playing, it will begin to download the data all over again if you want the sound to loop. What's more, streaming sounds and video require a server application, such as Flash Communication Server MX, to do the streaming. Another issue with streaming sounds is that sometimes the SWF file will rush to keep up with the streamed sound, so it might start dropping frames to keep up with the sound or video being streamed. If there is ActionScript on those frames, your code will be lost. On the plus side, streaming sound and video are the only useful solution to delivering very large files, video- or audioconferencing, or simulcasts (such as Major League Baseball games).