>>715219245Bud, it literally takes light over 87,000 years to move from one side of our galaxy to the other. Yeah, we can't count every single star in our galaxy because we can't see even a small tiny fraction of the stars in our galaxy, all we can do is point our telescopes into the sky, see oh there's this many stars in this area, and in this area this many stars, and then get a rough average as to the density of stars in this area and calculate that for the entire galaxy. Of course there's a huge error range, the center of our galaxy is one massive black hole and around that is the massive galactic bulge which contains a massive number of stars. Not to mention the spiral arms themselves which we can only see a fraction of with telescopes.
There's clearly hundreds of billions of stars in our galaxy alone. There's more stars in the universe than there are grains of sand on Earth.