Xvid is software that compresses music and video into the MPEG-4 format. Xvid-encoded files can be played with the popular, and free, VLC Media Player. If you don’t want to install VLC, you can probably find an Xvid codec for whatever player software that you are using.
Many files found on file-sharing networks like Usenet and BitTorrent are encoded with Xvid. So, you might see an NZB file titled like this:
My.Vacation.Video.2014.Xvid.avi.nzb
…or a torrent file like this:
My.Vacation.Video.2014.Xvid.avi.torrent
Posters put “Xvid” in the title because many people like to know which codec was used before they download a file. If you see “Xvid” in the title, that’s a good thing because you know that there won’t be a hassle when trying to play it.
Xvid is open-source and was developed as an alternative to the proprietary DivX codec. Most Xvid files can be played on DivX-compatible DVD players, TVs, Blu-ray players, etc.