Product Definitions
Disc formats
CD+G	CD+G, otherwise known as CDG or CD+Graphics, is the most commonly available karaoke format. The discs are standard audio CDs with extra information encoded on them to allow graphics to be displayed on a TV screen or monitor when played in a compatible player. These are NOT the same as DVDs although some newer DVD players are able to display the graphics correctly. CD+G tracks display the lyrics on a (usually) plain background. These discs can also be played in a standard CD player to get just the backing track.
VCD	VCDs, or Video Compact Discs, can be played in most DVD players and PC CD-ROMs. Some commercial CDG players can also play VCD discs These discs typically display a video in the background with lyrics overlaid in the front.
DVD	DVDs can be played in DVD players and PC DVD-ROMs, but care must be taken to check any region coding on the disc. Extra features on DVD karaoke discs will be listed with each individual disc.
Multiplex
Yes	Multiplex discs have the lead vocals recorded on one channel (typically the right channel) for guidance, most karaoke players will have a Multiplex (or MPX) button which can cancel the lead vocal and just leave the backing track and and backing vocals. The same effect can be achieved by altering the balance to cancel the right channel.
No	Non Multiplex discs only have the backing tracks and sometimes backing vocals recorded on them, there are no lead vocals available.
Mixed	These discs have each track recorded twice, once as non-Multiplex and once as Multiplex.