Another drawback is that some browsers require a plug-in to play audio and video. Older browsers, like Netscape 2.x, need to have a plug-in. The only way to stop the sound is, after the page has loaded, to click on the stop button. Most people find background sound like this a bit annoying, especially if it has been set to loop over and over. It can be used as background sound, or you can set it up with the controls on the page to let the user decide if they wish to hear the file.
Video is also a bit different in the two browsers.
With the addition of some plug-ins, more advanced control options can be added. Wav files are by far the largest, but their quality is also the best. If you wanted your page to have a bit of your favorite song or a vocal track to welcome visitors to your site, these are what you would use. Both are of high quality, but of even higher file size. As mentioned before, all older browsers require plug-ins to play video of any type.