Cubic Meters
A cubic meter is a metric unit of volume which is the equivelent space occupied by a cube with 1 meter on each of its sides.
Denoted by symbol "m³", it is a unit of measurement in the International System of Units (SI) and is generally used for larger volume measurements.
US liquid gallons
A US liquid gallon is a volume measurement used in the United States for liquids such as water, gasoline, and milk. One US liquid gallon is about 3.78541 liters. A standard bathtub is about 80 gallons of water and a car gas tank can hold anywhere between 12 and 20 gallons of gas.