100 thousand million stars
Stars are not scattered randomly through space, they are gathered together into vast groups known as galaxies. The Sun belongs to a galaxy called the Milky Way. Astronomers estimate there are about 100 thousand million stars in the Milky Way alone. Outside that, there are millions upon millions of other galaxies also!
It has been said that counting the stars in the Universe is like trying to count the number of sand grains on a beach on Earth.