the software. You can use as much as space as u want/need.
My notes generally just give a brief overview of a hand from what I saw. e.g.
limped from UTG+1 and then called CO's 4xBB raise w/ KJo .... pushed a J hi flop (20/40 - 8 handed - $22)
stuff like that. It all just builds up to the type of hands and situations that opp will play.