There are several variations on the basic auction form, including time limits, minimum or maximum limits on bid prices, and special rules for determining the winning bidder(s) and sale price(s). Participants in an auction may or may not know the identities or actions of other participants. Depending on the auction, bidders may participate in person or remotely through a variety of means, including telephone and the internet. The seller usually pays a commission to the auctioneer or auction company based on a percentage of the final sale price.
拍卖在基本形式之上存在着某些不同，包括限时、最低或最高竞投价格、以及用于决定竞价胜出者和成交价格的特别规则。参与拍卖的人不一定知道其他参与者的身份或者行为。根据拍卖形式的不同，竞投者可能会亲自出席，或者运用各种远程手段--例如电话和因特网--参与拍卖会。卖家一般会根据最终成交价格的一定比例付给拍卖商或拍卖公司佣金。
Primary types of auction 拍卖的主要种类
English auction 英式拍卖
English auction, also known as an open ascending price auction. This type of auction is arguably the most common form of auction in use today. Participants bid openly against one another, with each subsequent bid higher than the previous bid. An auctioneer may announce prices, bidders may call out their bids themselves (or have a proxy call out a bid on their behalf), or bids may be submitted electronically with the highest current bid publicly displayed. In some cases a maximum bid might be left with the auctioneer, who may bid on behalf of the bidder according to the bidder's instructions. The auction ends when no participant is willing to bid further, at which point the highest bidder pays their bid. Alternatively, if the seller has set a minimum sale price in advance (the 'reserve' price) and the final bid does not reach that price the item remains unsold. Sometimes the auctioneer sets a minimum amount by which the next bid must exceed the current highest bid.
英式拍卖，也称为公开增价拍卖。据称这种拍卖形式是当今最常见的拍卖方式。买家公开相互竞价，每次竞价都要比前一次的竞价更高。可以由拍卖师宣报价格，也可以由买家自己报价(或者请一位代理人代表买家报价)。当没有人愿意继续竞价时拍卖结束，出价最高者需支付所报出的价格。或者，如果卖家已经提前设定了最低售价("保留价")，而最终的竞价没有达到这个价格，拍卖品则不出售。有时候拍卖师会限定最低报价增幅，从而使下一次竞价必须高于当前的最高价格。
The most significant distinguishing factor of this auction type is that the current highest bid is always available to potential bidders. The English auction is commonly used for selling goods, most prominently antiques and artwork, but also secondhand goods and real estate. At least two bidders are required.
这种拍卖方式最显著的特点在于，当前最高竞价始终对潜在的买家公开。英式拍卖目前广泛用于商品出售，主要是古董和艺术品拍卖，也用于二手商品和房地产拍卖。这种拍卖需要至少两个买家的参与。
Dutch auction 荷兰式拍卖
Dutch auction also known as an open descending price auction. In the traditional Dutch auction the auctioneer begins with a high asking price which is lowered until some participant is willing to accept the auctioneer's price. The winning participant pays the last announced price.
荷兰式拍卖，也称为公开降价拍卖。在传统的荷兰式拍卖中，拍卖师以相对较高的价格起拍，然后逐步降低，直至有人愿意接受拍卖师开出的价格。胜出者需要支付最后一次宣布的价格。
The Dutch auction is named for its best known example, the Dutch tulip auctions. ("Dutch auction" is also sometimes used to describe online auctions where several identical goods are sold simultaneously to an equal number of high bidders.) In addition to cut flower sales in the Netherlands, Dutch auctions have also been used for perishable commodities such as fish and tobacco. In practice, however, the Dutch auction is not widely used.
荷兰式拍卖是因其最出名的一个案例--荷兰郁金香拍卖--而得名。("荷兰式拍卖"有时也指网上拍卖，这种网拍形式同时为数量相等的高竞价买家提供数件相同的物品。)荷兰式拍卖不仅被用于荷兰的鲜切花交易，还被用于出售某些易腐烂的商品，例如鱼和烟草。然而在实际中，荷兰式拍卖并未被广泛应用。
Sealed first-price auction 首价密封拍卖
Sealed first-price auction, also known as a first-price sealed-bid auction (FPSB). In this type of auction all bidders simultaneously submit sealed bids so that no bidder knows the bid of any other participant. The highest bidder pays the price they submitted.
首价密封拍卖也叫首价密封投标拍卖。根据这种拍卖方式的要求，所有买家须同时提交密封好的报价，因而没有人知道其他竞买者的报价。出价最高者支付其报出的价格。
This type of auction is distinct from the English auction, in that bidders can only submit one bid each. Furthermore, as bidders cannot see the bids of other participants they cannot adjust their own bids accordingly. Sealed first-price auctions are commonly used in tendering, particularly for government contracts and auctions for mining leases.
这种拍卖方式与英式拍卖的不同在于，每个买家只能出一次价。不仅如此，由于买家无法得知其他竞买人的报价，他们也无法相应地调整自己的报价。首价密封方式常用于投标，尤其是在政府项目和矿产租赁权拍卖中。
Vickrey auction 维克瑞拍卖
Vickrey auction, also known as a sealed-bid second-price auction. This is identical to the sealed first-price auction except that the winning bidder pays the second highest bid rather than their own. This is very similar to the proxy bidding system used by eBay, where the winner pays the second highest bid plus a bidding increment (e.g., 10%).
维克瑞拍卖，也称为第二价格密封拍卖。这种拍卖方式与首价密封拍卖基本相同，区别仅在于胜出者需要支付的价格是第二高的报价，而不是他自己的报价。这与易趣网所使用的代理人竞价系统相似，在这个系统中，胜出者需要支付第二高的报价，再加上一个报价的增额(如10%)。
Although extremely important in auction theory, in practice Vickrey auctions are rarely used.
尽管这种方式在拍卖理论中占据重要地位，但在实际中，维克瑞拍卖方式却很少被使用。
