Astrometry is the branch of astronomy dedicated to the precise measurement of the positions, movements, and distances of celestial objects, such as stars, galaxies, and solar system bodies. This field involves calculating fundamental parameters like stellar parallax, which measures the apparent shift of a star against background stars due to the Earth's orbital movement, allowing for the determination of distances. By mapping the three-dimensional coordinates and proper motions of these objects, astrometry helps scientists understand the kinematics and structure of the Milky Way galaxy, model the evolution of stellar systems, and trace the flow of matter across the cosmos. Modern astrometric surveys utilize sophisticated instrumentation and observational techniques to gather data on the motion of vast populations of stars.