Stellar measurements refer to the techniques used to determine the properties of stars, such as their distance, brightness, and size. Astronomers often use methods like parallax, which involves observing a star from different positions in Earth's orbit, to calculate its distance from us. Other techniques include measuring the star's luminosity and spectra to understand its temperature and composition. These measurements are crucial for understanding the universe. By knowing a star's distance and brightness, scientists can classify it within the Hertzsprung-Russell diagram, which helps in studying stellar evolution. Accurate stellar measurements also aid in exploring the structure of our Milky Way galaxy and beyond.