The document defines 15 essential terms used when art auctioning, including: appraisal, as is, auctioneer, bid, bought in, buyer's premium, conditions report, consignor, exhibition history, hammer price, increment, protecting a market, reserve, sell through rate, and white glove sale. It provides a brief 1-2 sentence definition for each term to concisely explain their meaning in the context of art auctions.