DD-1 track settings?

[AQ4life15]

Hey guys. Been a long time since I been on here. My friend has a smd dd-1 and thought about getting one. What does the tracks mean. I see ppl use -5db and -10db but what is really the difference and what track should I use. Thanks guys!

[soundstream15]

I use -10 not sure of the difference between the 2..I'm pretty sure if you play dj billy e and that stuff then -5