A character model is moved and fights as an individual piece, except that he may also join up with and fight alongside units of troops as described below.
When a character moves on his own he can ignore any penalties for crossing terrain and obstacles (apart from impassable terrain), and because he is not part of a larger formation he does not have to change direction by turning or wheeling - he can change direction freely as he moves. So, a character can move a fraction of his Movement distance, head off in another direction, move a little more, change direction again, and so on.