volume The volume of an object, or substance, is the amount of space it occupies. Volume is also the amount of space enclosed with a container - a bottle, for example.

'Mass' = the amount of 'stuff' an object is composed of. 'Volume' = the amount of space the object occupies. 'Density' = (the object's mass) divided by (the object's volume), which is the same as the amount of 'stuff' contained in each unit of space that the object occupies.

The volume of a solid object is a measure of the total amount of space the object occupies. The surface area of a solid object is a measure of the total area that the surface of the object occupies.