Hunter division is akin to the pleasure division in the Western horse industry. The emphasis of the judging is (or should) be on the horse -- his conformation, manners, way of going, and jumping style. The jumper division is the gaming of the English world. What counts is the time and leaving the course intact. No style points, but having solid control is a big help. That is the basic difference, but specific lists of faults can be found in the rulebooks of most associations, club shows, etc.
A stubborn horse walks behind you, an impatient one in front of you, but a noble companion walks beside you ~ Unknown