Volume measures how much space an object occupies. Capacity measures how much liquid or gas a container can hold.
Volume is measured in cubic units. A cubic unit is a unit of measurement.
The formula for the volume of a cube with sides that are one unit long is one unit times one unit times one unit which equals one cubic unit.
For example, Cubee "D", a standard unit of measurement, is one decimeter long. The volume of
Cubee "D" is 1dm X 1dm X 1dm which equals 1 (dm³).
Capacity is the amount of fluid or gas a container can hold. Capacity, in the metric system of measurement is usually measured in liters.
Volume and capacity are related, but they are not the same. Cubee "D" is a solid piece of wood but L is a plastic container. Cubee "D" fits exactly in L.