One of the galaxies you may know is the Milky Way. Everything in galaxies is held together by gravity. The Milky Way Galaxy has a black hole in the middle. On the outside there are starts swirling around. Also the solar system is swirling around, and the Earth is in the solar system. That means you are swirling around too when you are not knowing it. You can also see the Milky Way galaxy if you don’t believe me. Go to a Californian desert, look for a dust band. Here is a picture of one.
Source materials: https://spaceplace.nasa.gov/galaxy/en/
WRITTEN BY IMAD IN 4TH GRADE. Hope you had a great experience. Welcome to space!!!!!!!!!!!!!!!!!!!!!!!!!