Using Split Mode, allows you to play two different voices, or instruments, one one the left, and one on the right of the keyboard. (for example, a bass guitar to the left, and a piano to the right)
Again, any combination of voices can be split.
The left voice (e.g. Bass) will be played on the same key range, as the auto accompaniment chords. Keys to the right of the 'Split Point' will play the right voice (e.g. piano)
The Split point can be changed from it's default setting, to any point on the keyboard. More about that later. In the video below, I shall use the default setting.