Specific volume is defined as the amount of [[Volume|volume]] occupied by a [[Substance|substance]] per unit [[Mass|mass]]:
$\nu=\dfrac{V}{m}$
Where $\nu$ is specific volume, $V$ is volume, and $m$ is mass.
Density ($\rho$) is defined as the amount of mass of a substance per unit volume it occupies:
$\rho=\dfrac{m}{V}$
Specific volume and density are the reciprocal of one another:
$\nu=\dfrac{1}{\rho}$