It is a French design and is more difficult to build than the hip or gable roof. It actually features two slopes within one on each side. The bottom part of the roof slope is steeper so that the pitch of the roof barely starts. This allows more room on the inside and in most cases creates an extra space.
Dutch roof is basically a hip roof with a small gable at either end. The result is easier access to the lower portion of the roof with the added benefits of natural light and extra space.