What is volume
Volume tells something about the size of an object. The SI unit of volume is cubic meter (m3). The volume of objects with a cubical shape is obtained by multiplying the width, depth and length. For spherical objects it is a bit more complicated.

A well known experiment to measure the volume of a solid object is taking a graduated cylinder which contains water. Put the object in the cylinder, and the difference in litres equals the volume of the solid object.