A Galaxy is a large collection of stars; there are around 200,000 million stars in our galaxy the Milky Way, which is more than 20 stars for every person on the Earth. There are more galaxies in the universe than there are stars in our own galaxies. There are about 400,000 million galaxies in the Universe. Some are bigger than ours and many are smaller.
Hubble Space Telescope image of Galaxy NGC 3310, known as a "starburst" it produces Stars at far above the normal rate.