Parallax is a technique used in astronomy to measure the distance to nearby stars. It involves observing the position of a star against a background of more distant stars at two different points in Earth's orbit around the Sun. By measuring the angle between the two lines of sight to the star, astronomers can calculate the star's distance using trigonometry. The closer the star is to Earth, the greater its parallax angle will be. This is because the star appears to shift its position more significantly relative to the background stars as Earth moves around the Sun. By studying the parallax angles of various stars, astronomers can create a three-dimensional map of our Milky Way galaxy and determine the distances to thousands of stars. Parallax also plays a crucial role in determining the distances to objects in our Solar System, such as asteroids, comets, and even planets. By measuring the apparent shift in position of these celestial bodies against a background of stars, astronomers can accurately calculate their distances from Earth. Overall, parallax is a powerful tool in astronomers' toolkit for measuring the vast distances in our universe and gaining a better understanding of the celestial objects that surround us.