gd123 did a great job of giving you the details. However, to import MP3G or ZIP songs into Hoster, when you do not own the discs the songs came from can get you into FEDERAL LAW problems, and you can loose ALL YOUR computers, karaoke gear, discs, speakers, even your car/van you use to transport everything to shows with.
In other words, as Dale tried to say, DO NOT IMPORT songs into Hoster that you don't own. 