What are Multi's?

Hi I have been making beats with just track and sequence and song mode. I looked in the manual and google searched and also searched this site. I would imagine its something like multi track or something. I am wonder what MULTI mode it is and why I would need it. Thanks

-Phoggy

Settings, Programs and Samples.

Quicksave: Multi + Sequences = Entire Song

Thanks. This helps me start understanding multi's. I still am a bit confused.