There are tens of thousands of galaxies and our galaxy, The Milky Way, is just one of them. Galaxies have many shapes and sizes; however, they have the commonality of gravity, stars, gases, dust, dark matter, and remnants of planets and stars that have exploded. Actually, the significant portion of galaxies are elliptical and are believed to have massive black holes right in the center.
The universe contains all of space, including the many galaxies, planets, stars, and all other forms of energy or mater. The universe is such a vast expanse that it is a breathtaking collection of space and time, filled with everything you could imagine and some things you could not. The theory of the creation of the universe is an enigma in that there are so many theories, including scientific, and religious and not just one religion. There are many religions that have their idea of the formation of the universe.