They are held there by their mutual gravitational attraction.
No stars are actually a galaxy. All stars are stars and all galaxies are galaxies. Stars are found in galaxies. Some galaxies look like tiny dots in our night sky, so might look like a star, but they are not stars; they are galaxies.
All stars and galaxies are in the universe.
Yes, there are stars between galaxies. When there are collisions or interactions between galaxies, stars can be ripped out of the galaxies. These stars will then wander into space between galaxies. Such stars have been observed with the Hubble Space Telescope. Taken from http://curious.astro.cornell.edu/question.php?number=384
Smaller galaxies do. Larger galaxies contain billions or even trillions of stars.
Galaxies are the massive collection of stars. Therefore galaxies could not have formed without stars.
A super massive Black hole present in the centre of almost all galaxies have tedency to bind up all the things . Our milky also have super massive black hole in it's centre .
Stars and Galaxies are related because a galaxy is a system of billions of stars, gases, and dust.
Stars
Bigger galaxies. And stars.
Galaxies ARE groups of stars. Lots of stars though. Not just like 2 or 3...
the stars are in the night skies
Galaxies are vast collections of stars. So I guess you could say that a big group of stars forms a galaxy. Our galaxy has many big clusters of stars within it, so not all star clusters are galaxies. If you have a cluster of several million or billion (or trillion) stars surrounded by a lot of empty space, that is probably a galaxy.