Galaxies act as the cities of the Universe, from small "towns" with only a few tens of thousands of stars to massive metropolises boasting billions.  What makes up a galaxy?  How are these galaxies affected by the environment around them?  And most importantly, how is it possible to study objects that are billions of light years away and gain knowledge about their inner workings?  We'll take a broad look at galaxies and the universe as a whole, from spirals to ellipticals, from black holes to stars, and from dark matter to dark energy.