The Italian Hitch is an extremely useful knot as it can be used for belaying, abseiling, and rigging. It is a friction device which creates friction by rubbing on the hardware or object, usually a carabiner, so the descent can be controlled in a belay mechanism. But since this knot leaves a lot of bends in the rope, the Italian Hitch is used only as back-up or for emergency situations.
As a belaying knot, this hitch allows great flexibility in system design and operation. The knot is controlled from the front, as opposed to a belay plate which must be controlled from behind. Maximum breaking is obtained by having the ropes parallel on the load side of the carabiner.