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.
拍賣在基本形式之上存在著某些不同，包括限時、最低或最高競投價格、以及用於決定競價勝出者和成交價格的特別規則。參與拍賣的人不一定知道其他參與者的身份或者行為。根據拍賣形式的不同，競投者可能會親自出席，或者運用各種遠程手段——例如電話和網際網路——參與拍賣會。賣家一般會根據最終成交價格的一定比例付給拍賣商或拍賣公司佣金。
Primary types of auction 拍賣的主要種類
English auction 英式拍賣
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.
英式拍賣，也稱為公開增價拍賣。據稱這種拍賣形式是當今最常見的拍賣方式。買家公開相互競價，每次競價都要比前一次的競價更高。可以由拍賣師宣報價格，也可以由買家自己報價(或者請一位代理人代表買家報價)。當沒有人願意繼續競價時拍賣結束，出價最高者需支付所報出的價格。或者，如果賣家已經提前設定了最低售價(「保留價」)，而最終的競價沒有達到這個價格，拍賣品則不出售。有時候拍賣師會限定最低報價增幅，從而使下一次競價必須高於當前的最高價格。
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.
這種拍賣方式最顯著的特點在於，當前最高競價始終對潛在的買家公開。英式拍賣目前廣泛用於商品出售，主要是古董和藝術品拍賣，也用於二手商品和房地產拍賣。這種拍賣需要至少兩個買家的參與。
Dutch auction 荷蘭式拍賣
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.
荷蘭式拍賣，也稱為公開降價拍賣。在傳統的荷蘭式拍賣中，拍賣師以相對較高的價格起拍，然後逐步降低，直至有人願意接受拍賣師開出的價格。勝出者需要支付最後一次宣布的價格。
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.
荷蘭式拍賣是因其最出名的一個案例——荷蘭鬱金香拍賣——而得名。(「荷蘭式拍賣」有時也指網上拍賣，這種網拍形式同時為數量相等的高競價買家提供數件相同的物品。)荷蘭式拍賣不僅被用於荷蘭的鮮切花交易，還被用於出售某些易腐爛的商品，例如魚和菸草。然而在實際中，荷蘭式拍賣並未被廣泛應用。
Sealed first-price auction 首價密封拍賣
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.
首價密封拍賣也叫首價密封投標拍賣。根據這種拍賣方式的要求，所有買家須同時提交密封好的報價，因而沒有人知道其他競買者的報價。出價最高者支付其報出的價格。
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.
這種拍賣方式與英式拍賣的不同在於，每個買家只能出一次價。不僅如此，由於買家無法得知其他競買人的報價，他們也無法相應地調整自己的報價。首價密封方式常用於投標，尤其是在政府項目和礦產租賃權拍賣中。
Vickrey auction 維克瑞拍賣
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%).
維克瑞拍賣，也稱為第二價格密封拍賣。這種拍賣方式與首價密封拍賣基本相同，區別僅在於勝出者需要支付的價格是第二高的報價，而不是他自己的報價。這與易趣網所使用的代理人競價系統相似，在這個系統中，勝出者需要支付第二高的報價，再加上一個報價的增額(如10%)。
Although extremely important in auction theory, in practice Vickrey auctions are rarely used.
儘管這種方式在拍賣理論中佔據重要地位，但在實際中，維克瑞拍賣方式卻很少被使用。