XViD videos differ from YouTube in that they are higher resolution
& require an actual video player or codec for playback. These video
files can also be used for playback on DVD players or be used to
convert to DVD or any Portable Media Player (Phone, iPod, etc).

If you're video player cannot playback the file, you need to install a
codec that will decode the XViD format, Available for
Windows or MacOSX.