A galaxy is a group of stars that are held close together. They come in different shapes and sizes. Some have millions of stars, others have billions.
Most galaxies look round like a ball or oval like an egg. These are called elliptical galaxies.
Our galaxy, the Milky Way, looks like a fried egg – fat in the middle and thin on the edge with arms like an octopus. This type of galaxy is called a spiral galaxy.
Some galaxies have no shape at all and are called irregular.
Astronomers believe there are 125 billion galaxies in the universe. That’s a lot of stars.