About Windows Media
Microsoft Windows Media is the underlying technology that you use to create, deliver, and play digital media content in Windows Media Format. Windows Media uses to compress large digital media files for network delivery, as well as for storing files for local playback. Windows Movie Maker merges components of Windows Media into one easy-to-use package, so you can create movies that you can share with others on the Web, as an attachment in an e-mail message, or on a recordable CD.
You can save the video and audio files you capture as with a .wmv file name extension (for video files) or a .wma file name extension (for audio files, such as a narration). When you save your final movie, it is saved in Windows Media Format by default.