text: A white dwarf is both more massive and denser than a brown dwarf.   A white dwarf was once a fully-qualified ordinary star, producing energy from nuclear fusion.   But a brown dwarf was never massive enough for nuclear fusion to start.   Density of a white dwarf about 2 tonnes/cc.   Mass; within an order of magnitude the mass of the Sun.   Density of brown dwarf; a few grams/cc.   Mass less than a fiftieth that of the Sun.