Reduce the effort needed to move a load vertically. An incline decreases the amount of work you need to put in to lift a load. If you lifted the load directly up, you would need to put in enough energy to counter the whole weight of the load. If you push the load up an incline, however, your horizontal force will only need to counter the x-component of gravity's force, which is smaller in magnitude, so it takes less effort to push the load up a slope.
