There are several technologies used for storing audio and video, and most players and portable devices support only a subset of all technologies.

To help you decide what format you should choose, use the overview below:

Technology Windows Media Player Apple iTunes Apple iPod Syncs with MGTEK Dopisp
MP3 Audio Yes Yes Yes Yes (preferred)
WMA (Windows Media Audio) Yes Can be imported and converted No Yes, conversion to MP3 required
DRM protected WMA, purchased from online stores Yes No No No
AAC Audio (M4A) WMP12: Yes

WMP11: Codec required for playback, poor tag support

Yes Yes Yes (preferred)
Other Audio formats (OGG, FLAC, etc.) Codec required for playback, poor tag support No No Yes, conversion to MP3 required
DRM protected AAC Audio (M4P), purchased from iTunes store No Yes Yes Yes, iPod needs to be synced once with iTunes first.
AVI Video (various formats) Yes No No No
MPEG-4 Video (MP4 or M4V) WMP12: Yes

WMP11: Codec required for playback, poor tag support

Yes Yes (1) Yes (preferred)
H.264 Video (MP4 or M4V) WMP12: Yes

WMP11: Codec required for playback, poor tag support

Yes Yes (1) Yes (preferred)

(1) MPEG-4 up to 2.5 Mbps or H.264 low complexity profile required, up to 640x480.

Summary

If you wish to sync your Apple iPod with Windows Media Player, we make the following recommendations:

See Also

Adding MPEG-4 Support to WMP 11