以上单词均可用于指不经金钱而直接交换商品或服务等, 称为“易货贸易”。其中，barter为最正式和典型术语，常指不使用任何具抽象价值的中介物，也不用任何中间人，自己直接以物换物，如农夫用粮食交换靴子（barter grain for boots)[1]。 倘若农夫不是为自己使用而换取靴子，而是用靴子交换其他物 品或用于其他目的，此时则可以说他是想trade the boots with sb else for sth he really wants[2]。在 bartering 和 trading 中，人们必 须 exchange one item for another。swap 可用作等同 barter,但没有 barter 正式。
 
[1] "Barter is the most formal and most specific of these. It means a system of exchange in which goods and services are traded without the use of money as a medium of exchange. "Cf. Douglas Greenwald, The Concise McGraw-Hill Dictionary of Modem Economics, at p. 23，McGraw-Hill, Inc. (1983).
[2] Cf. The Editors of The Reader's Digest, Use the Right Word, at p. 37，The Reader's Digest Association Proprietary Ltd. (1971 ).
[3] Id. at p. 37.