An online auction is the event or process that involves a good or service being sold and bought in a certain manner, that being the rules that define that particular auction and with an auctioneer(s) selling and bidder(s) buying. Bidding is the process of competing to buy the good or service being sold. In other words, the auction includes both the selling and buying process by the auctioneer(s) and bidder(s), respectively, and bidding just involves the buying process done by the bidders.