chord input or arpeggio?

i posted this in the 2500 JJ forum as well but i wanted to check here too since there are so many more users. i've seen someone mention a feature called "chord input" in regards to the JJ OS. what is this? also, i've heard some people talk about an arpeggio creation feature. what is this?

check OS2 and OS2XL

i looked through the manual but didnt see anythng on either of them....