A Solar system comprises a sun and its orbiting planets along with all the moons and space objects–including space dust–that also orbit the sun. There are billions of these solar systems in space.
Galaxies are bigger; they comprise billions of solar systems and are separated from one another by vast space. Our galaxy is the Milky Way. Besides our sun and its solar system, there are 200 billion to 400 billion other stars (suns). That means it’s likely there are well over 100 billion solar systems within our own galaxy. Wow.