A floor order, as defined by the Convention Industry Council, is an "order for exhibitor services placed on-site after exhibit setup begins."
Exhibitor services encompass a wide range of products and services, from utilities such as electricity, to supplies (surge protectors, flooring, lighting) and labor (booth cleaning, exhibit setup/dismantle).
Floor orders are often more expensive than advance orders (which are, naturally, orders for services placed before the start of the event).
You can save your company hundreds of dollars by placing an advance order, rather than a floor order. All it takes is a little advanced planning. For more ways to boost your trade show ROI, click on the preceding link.