Here's the Andromeda Galaxy (M31) without the stars and other clutter from our own galaxy in the way. I have processing tools that will algorithmically remove stars from an image, and it does a reasonable job. What I'm showing here is what Andromeda would look like if you could travel from our location on the Orion Spur (a minor branch off one of the Milky Way's spiral arms), pass through the Perseus Arm, to the edge of our galaxy, and then take some pics of M31. Our star, the Sun, sits in the middle of one side of our galaxy. We are so used to seeing a star field in astro images we do not realize all the stars we can see in the night sky--with our eyes, are in our own galaxy. Some of those pinpoints of light are galaxies themselves but are so far away they appear no different from stars to our eyes. In this image of M31 the two star-like objects above and below Andromeda are M110 (larger, below) and M32 (above). These two are actually satellite galaxies that orbit Andromeda. Yes, just as stars have planets, and planets have moons, large galaxies can capture other galaxies in their gravitational pull. Our galaxy, the Milky Way, has several in orbit, including the Large and Small Magellanic Clouds.