A milliliter is 1/1,000 of a liter, meaning that there are 1,000 milliliters in a liter. A liter is a measurement of volume in the metric system. Converting to different units of volume within the system is easy and generally requires only moving the decimal point.
The following prefixes are used in the metric system: nano- means billionth, micro- means millionth, milli- is thousandth, centi- is hundredth, deci- is tenth, deca- means ten, hecto- means hundred, kilo- means thousand, mega- means million and giga- means billion. In other words, a nanoliter is one billionth of a liter, a centimeter is 1/100 of a meter and a decaliter is 10 liters.