Volume is the space enclosed by a three dimensional body. To find out the volume of such a body, three factors are taken into account: height, width and depth.
Depending on the type of figure, there are different formulas for finding out volume. A rectangular prism has a volume equal to the product of its three dimensions. A sphere has a volume equal to four-thirds time pi times the radius cubed. The volume of a pyramid is equal to one-third the area of the base times the height. There are other formulas for such shapes as cylinders and ellipsoids, and using these basic formulas, and three-dimensional shape (such as the Sydney Opera House), can be broken down into basic shapes and its volume calculated.
While three dimensional geometry such as this is not actually that confusing, and only requires a middle school grasp of mathematics, the ramifications of volume are many and far reaching. Because volume has three factors, it can increase very rapidly, which is responsible for such important things as the square-cube law.