I'm researching the creation of galaxies and I've came across these two terms. In my research on theory says that the fluctuations in density of space trapped gas and dust, which formed protogalactic galaxies that then forms a galactic disk. The other one says that the clumping of dark matter and regular matter created protogaxies that then combine to form a galaxy. Which theory is more accurate and what is the difference between these two terms. Thanks!