Risers are plastic or hard rubber pieces between the Deck and the Trucks. They are used to help stop wheelbite by raising the deck up away from the wheels. Shock pads are softer, as they bend and compact. This absorbs stress the baseplate puts on the deck during landings. The term "risers" and "shock pads" are wildly swapped between as a riser will do the job of a shock pad and a shock pad will do the job of a riser.