Why the stars near and outter …

Most of the stars you see in the night sky with your naked eye are individual stars inside our own galaxy. It takes telescopes to see the stars outside our galaxy or even to see other galaxies. The stars in our galaxy are all orbiting in a nearly circular path around the center of the galaxy. They do this because the immense combined mass of the galaxy, most if it near the center, creates immense gravity that pulls all the stars in our galaxy into circular orbits. In addition, each star in the galaxy has a small random motion relative to the overall galactic rotation. The same concepts apply to stars in other galaxies. Each star orbits its galaxy's center and has a slight random motion on top of this. Each star does not careen randomly about like a drunkard. Rather, each star travels on a smooth, nearly-straight trajectory as dictated by its own momentum and the local gravitational field. But when comparing the motion of many stars in a galaxy and subtracting out their galactic rotation, you end up with a random distribution. The reason for this is simply the randomness of the materials from which the stars formed, and the tendency of objects to drift under their own inertia in nearly the same path for eons in the near-vacuum of space.