This document defines various metric units for measuring volume, including those over and under 1 liter such as exaliters, milliliters, and picoliters. It provides the prefixes and their corresponding multipliers to convert between these units, where units over 1 liter are multiplied by powers of ten and units under 1 liter are divided by powers of ten. The document serves as an introduction to the different metric volume units and how to change between them.