# Semiclassical Approximation

In many books I read about semiclassical approximation applied to the field of Bose-Einstein condensation. But I don't understand what it really means. For example I read that an expression like this $f_\textbf p (\textbf r) \frac{d^3\textbf rd^3\textbf p}{(2\pi \hbar)^3}$ for the state density. Have anybody a good explanation applied to this case? Or a general definition of semiclassical approximation?