A system of charged classical particles moving in a uniform positive neutralizing background is known as a one-component plasma (OCP). This is well described by the hyper-netted chain equation (see classical-map hypernetted-chain method or CHNC). An essentially very accurate way of determining the properties of classical fluids is provided by the method of molecular dynamics. An electron gas confined in a metal is not a classical fluid, whereas a very high-temperature plasma of electrons could behave as a classical fluid. Such non-classical Fermi systems, i.e., quantum fluids, can be studied using quantum Monte Carlo methods, Feynman path integral formulation, and approximately via CHNC integral-equation methods.