Its both you noobs!
When a star evolves it passes though a brown dwarf stage, then can be free floating if it doesn't have a host star to orbit (as it continuously evolves becoming a rocky world in its center, forming the new life hosting "planet" in its interior).
Its easy! Big, hot and bright (what they call stars).... smaller, gaseous, not so bright (what they call brown dwarfs)... smaller, rocky (differentiated) not shining any longer (what they call planet), dead cold world that smashes into other bigger bodies making shrapnel (asteroids/meteorites)...
See? Its not hard to conceptualize!