What is volume and how is it measured?

Volume is the amount of space that a substance or object occupies, or that is enclosed within a container. It is measured in Volumetric units. 

Volume is the quantity of three dimensional space enclosed by a closed surface that a solid, liquid, gas, or plasma or shape contains. And the volume of a container is generally understood to be the capacity of the container , the amount of of fluid or a gas or liquid that the container could hold rather than the amount of space the container itself displaces