newb question: What is and does the msb/lsb function do

i just recently bought the mpc1000 and im reading the online instruction manual and it doesn't really define the 2 functions in debt so I was wondering if someone can explain to me or even a link to a website that explains these. thank you

I believe and dont quote me, that it has to do with program banks. For example, if you have a keyboard with banks A, B, C, etc. You can program the mpc to switch banks for different sounds. It's usually used at live performances for quick changes in between songs and/or changes within one song.

Again, im not absolutely positive thats what its for but i think im close.