Oz is an English unit, the abbreviation of the symbol ounce, which is called "ounce" in Chinese (translated into ounces in Hong Kong) and also called English ounces as a unit of weight.

The history of ounces:

It was the earliest time to drink different wines and choose different wine glasses. The capacity of the cup is the most important. In history, ounces (English is Ounce, abbreviated as oz) were used as the liquid unit of wine. Both British and American systems of units have this unit, which is slightly different, for example, English 1 ounce is 28.41ml; American 1 oz is 29.57ml. 16 oz 1 pint (made in USA).

The international system of units, which expresses the capacity of wine utensils in milliliters. 30ml instead of 1 oz.

The United States does not use metric measures. A pound is about 454 grams, which is equivalent to 16 ounces. A pound is about the weight of a pint (less than 0.5 liter) of water, so there is a saying that "a pint is a pound, and the world is like this". A pint also contains sixteen ounces, at least in American weights and measures; In the British system of weights and measures, a pint is about 20 ounces, so this proverb does not apply to British units, although the English liquid ounce is about 4% less than the American liquid ounce. So we use both liquid ounces and dry ounces to measure weight, and they are also different in English and American weights and measures.