We've learned a lot about stars! We know how they form, and we know that most of them exist in galaxies. But how are they arranged within galaxies? And are there different types of galaxies or are they all the same? There is a lot to discuss here, so let's expand our understanding of star systems and galaxy types! Watch the whole Astronomy/Astrophysics playlist: http://bit.ly/ProfDaveAstronomy Classical Physics Tutorials: http://bit.ly/ProfDavePhysics1 Modern Physics Tutorials: http://bit.ly/ProfDavePhysics2 Mathematics Tutorials: http://bit.ly/ProfDaveMaths General Chemistry Tutorials: http://bit.ly/ProfDaveGenChem Organic Chemistry Tutorials: http://bit.ly/ProfDaveOrgChem Biochemistry Tutorials: http://bit.ly/ProfDaveBiochem Biology Tutorials: http://bit.ly/ProfDaveBio EMAIL► ProfessorDaveExplains@gmail.com PATREON► http://patreon.com/ProfessorDaveExplains Check out "Is This Wi-Fi Organic?", my book on disarming pseudoscience! Amazon: https://amzn.to/2HtNpVH Bookshop: https://bit.ly/39cKADM Barnes and Noble: https://bit.ly/3pUjmrn Book Depository: http://bit.ly/3aOVDlT