There are two kinds of conflict: internal and external. The external conflict tends to be the bigger one in most stories: the bully who refuses to let the scrawny kid pass through the school hallways in peace. The internal conflict is smaller, but in my opinion, the more important one. A character cannot grow and change without resolving or at least acknowledging the inner conflict.
In our bully story (not great, I know, but it's what I plucked from the ether just now) the external conflict is about how the kid is going to make it through the school year without getting creamed by the bigger kid who's making it impossible for him to move through the school. Clearly this would be a scary situation, so the inner conflict is in that fight or flight reflex that's built into us all. Our scrawny young hero needs to overcome his terror and face up to the bully in order to win his respect or to show him up as the coward he really is.
In that situation, the conflicts are fairly simple. They don't have to be. I'm rewriting a section toward the end of Tail Lights right now, to add more conflict and up the tension in that particular part. Because I have two characters' stories running through the book, maintaining and balancing the conflict in both threads is a little like walking a tightrope. When one character's conflict begins to resolve, the other one's needs to ramp up. I've discovered a point where this doesn't happens, and need to up the stakes.
Do you find balancing the conflict and resolution in your work a challenge?