here you will find all the explanations that are used:
http://www.vcdquality.com/index.php?page=faq#4
because it says ts is telesync. telesync is (video from cam, audio stereo)
TS is telesynch which means its a cam with in-line audio
PreVail are the group that released it
Xvid is the codec used to encode it to avi - which means it will play on any dvd player that can handle divx. 'scene' releasers use xvid in preference because its free.