A Rib Rack is a device that is used to hold multiple racks of BBQ ribs during cooking.
Rib Racks typically hold the ribs upright instead of laying flat on a grate. This is done to save space so you can cook more ribs.
Look for rib racks that are easy to clean. The bits of BBQ goodness can get stuck in all the nooks and crannies on the more complex racks and make them difficult to scrub.