The ounce, which can refer to a number of various measures of mass, weight, or volume, was derived almost exactly in its current form from the uncia, an Old Roman unit of measurement.
What is Cup?
1 cup, 1/2 cup, 1/3 cup, 1/4 cup, and 1/8 cup are the standard cookery measuring cup sizes. 1 cup equals 8 fluid ounces in US Standard Volume. It is a cooking measurement.