Microliters
Microliters are a unit of volume in the metric system used to measure very small amounts of liquid. One microliter is equal to one millionth of a liter. This tiny unit of measurement is often denoted by the symbol μL. To put it into perspective, a single drop of water is roughly equivalent to about 50 microliters.
US fluid ounces
A US fluid ounces (sometimes referred to simply as an ounce) is a unit of volume used in the United States to measure liquids. One US fluid ounce is about 0.0296 liters.