com·mod·i·ty

In economics, a commodity is an economic good that has full or substantial fungibility [可替代性]: that is, the market treats instances of the good as equivalent or nearly so with no regard to who produced them.

Fungible, which derives from the Latin verb fungi, meaning "to perform" (no relation to the noun fungus and its plural fungi), is a word that often shows up in legal and political contexts. Something fungible can be exchanged for something else of the same kind.

The price of a commodity good is typically determined as a function of its market as a whole: well-established physical commodities have actively traded spot and derivative markets. The wide availability of commodities typically leads to smaller profit margins and diminishes the importance of factors (such as brand name) other than price.

Something that is well-established has existed for a long time and is respected or trusted by people.

Profit margin, net margin, net profit margin or net profit ratio is a measure of profitability.

margin (commerce): difference between cost price and selling price. "margin of error" is attested by 1889. Stock market sense of "sum deposited with a broker to cover risk of loss" is from 1848.

marginal (technical): relating to a change in cost, value etc when one more thing is produced, one more dollar is earned etc.

marginal revenue

Most commodities are raw materials, basic resources, agricultural, or mining products, such as iron ore, sugar, or grains like rice and wheat. Commodities can also be mass-produced unspecialized products such as chemicals and computer memory. 卖咖啡豆好像很不挣钱。

The word commodity came into use in English in the 15th century, from the French commodité, "amenity [方便设施], convenience". Going further back, the French word derives from the Latin commoditas, meaning "suitability, convenience, advantage". The Latin word commodus (from which English gets other words including commodious [宽敞的] and accommodate) meant variously "appropriate", "proper measure, time, or condition", and "advantage, benefit". A house or room that is commodious is very big.

The law of diminishing marginal utility says that the marginal utility from each additional unit declines as consumption increases. 边际效用递减规律。没有电脑时，电脑很新奇，人们愿意花很多钱买。然后台式机人们玩腻了，玩笔记本，笔记本玩腻了，玩手机。AR, VR, 智能音箱？手机能干的事情太多了。

六级/考研单词: commodity, equivalent, derive, verb, noun, plural, seldom, illicit, physics, diminish, brand, lucrative, commerce, differentiate, deposit, broker, ore, grain, wheat, compute, farther, accommodate, utility