It looks like a misty streak across the sky. Between the stars are vast clouds of gas and dust known as nebulae, the latin word for mist. They are best seen in clear country skies away from smoke and streetlights. Many stars congregate in clusters, some of which are visible to the naked eye. Open clusters are found along the spiral arm of our galaxy while Globular clusters are found well away from the plane of the Milky Way.
Stars are so far away that it is impossible to measure their distances only in kilometers.
Therefor Astronomers and scientists have found various other methods to measure such huge distances . This distance is equal to 150,000,000 km. The distance at which a star would have a parallax of one second of arc. One parsec equals 3.2616 light years. If you become interested in astronomy ,the first step step should be to learn how to recognize the stars and the planets.